codegen: Emit diagnostics pragmata for GCC 14 compatibility

GCC 14 refuses to compile C sources with certain type errors, to
provide prompt feedback to programmers about mistakes.  Vala
does not generate valid C in some cases (see issues #358, #1005,
#1408, and perhaps others).  As a stop-gap measure, this commit
introduces pragmata to turn the relevant GCC diagnostics into
warnings.  For experimentation, this can be avoided at C compilation
time by defining the VALA_STRICT_C macro.

Submitted upstream: <https://gitlab.gnome.org/GNOME/vala/-/merge_requests/369>

diff --git a/ccode/valaccodefile.vala b/ccode/valaccodefile.vala
index f61da07dfa103986..37f4978673b742db 100644
--- a/ccode/valaccodefile.vala
+++ b/ccode/valaccodefile.vala
@@ -161,6 +161,7 @@ public class Vala.CCodeFile {
 			writer.line_directives = line_directives;
 
 			comments.write (writer);
+			write_compiler_compatibility (writer);
 			writer.write_newline ();
 			feature_test_macros.write (writer);
 			writer.write_newline ();
@@ -218,6 +219,26 @@ public class Vala.CCodeFile {
 
 		return true;
 	}
+
+	static void write_compiler_compatibility (CCodeWriter writer) {
+		writer.write_string ("#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14");
+		writer.write_newline ();
+		write_compiler_compatibility_pragma_warning (writer, "GCC", "-Wimplicit-function-declaration");
+		write_compiler_compatibility_pragma_warning (writer, "GCC", "-Wincompatible-pointer-types");
+		write_compiler_compatibility_pragma_warning (writer, "GCC", "-Wint-conversion");
+		write_compiler_compatibility_pragma_warning (writer, "GCC", "-Wreturn-mismatch");
+		writer.write_string ("#endif");
+		writer.write_newline ();
+	}
+
+	static void write_compiler_compatibility_pragma_warning (CCodeWriter writer, string compiler, string warning) {
+		writer.write_string ("#pragma ");
+		writer.write_string (compiler);
+		writer.write_string (" diagnostic warning \"");
+		writer.write_string (warning);
+		writer.write_string ("\"");
+		writer.write_newline ();
+	}
 }
 
 [Flags]
diff --git a/tests/annotations/deprecated-delegate-minimal.c-expected b/tests/annotations/deprecated-delegate-minimal.c-expected
index 5f70e82fde933006..f3258f1f24eb7440 100644
--- a/tests/annotations/deprecated-delegate-minimal.c-expected
+++ b/tests/annotations/deprecated-delegate-minimal.c-expected
@@ -1,6 +1,13 @@
 /* annotations_deprecated_delegate_minimal.c generated by valac, the Vala compiler
  * generated from annotations_deprecated_delegate_minimal.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 typedef void (*Foo) (void) G_GNUC_DEPRECATED ;
diff --git a/tests/annotations/deprecated-enum-minimal.c-expected b/tests/annotations/deprecated-enum-minimal.c-expected
index c809a7aef5b2bb19..54fa530e6d9417b3 100644
--- a/tests/annotations/deprecated-enum-minimal.c-expected
+++ b/tests/annotations/deprecated-enum-minimal.c-expected
@@ -1,6 +1,13 @@
 /* annotations_deprecated_enum_minimal.c generated by valac, the Vala compiler
  * generated from annotations_deprecated_enum_minimal.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 typedef enum  {
diff --git a/tests/annotations/deprecated-method-minimal.c-expected b/tests/annotations/deprecated-method-minimal.c-expected
index 02168bc6ca3be60c..734c5f170f6d459e 100644
--- a/tests/annotations/deprecated-method-minimal.c-expected
+++ b/tests/annotations/deprecated-method-minimal.c-expected
@@ -1,6 +1,13 @@
 /* annotations_deprecated_method_minimal.c generated by valac, the Vala compiler
  * generated from annotations_deprecated_method_minimal.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/annotations/deprecated-property-minimal.c-expected b/tests/annotations/deprecated-property-minimal.c-expected
index cebd8f46d6a2bca9..b393f8ce349fc0b7 100644
--- a/tests/annotations/deprecated-property-minimal.c-expected
+++ b/tests/annotations/deprecated-property-minimal.c-expected
@@ -1,6 +1,13 @@
 /* annotations_deprecated_property_minimal.c generated by valac, the Vala compiler
  * generated from annotations_deprecated_property_minimal.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/annotations/deprecated-struct-minimal.c-expected b/tests/annotations/deprecated-struct-minimal.c-expected
index cbc9b5d9de97e8f5..5b12fef3f2c14852 100644
--- a/tests/annotations/deprecated-struct-minimal.c-expected
+++ b/tests/annotations/deprecated-struct-minimal.c-expected
@@ -1,6 +1,13 @@
 /* annotations_deprecated_struct_minimal.c generated by valac, the Vala compiler
  * generated from annotations_deprecated_struct_minimal.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 typedef struct _Foo Foo;
diff --git a/tests/annotations/deprecated.c-expected b/tests/annotations/deprecated.c-expected
index c867d18f83f60f65..c317ea13a0fc4ad4 100644
--- a/tests/annotations/deprecated.c-expected
+++ b/tests/annotations/deprecated.c-expected
@@ -1,6 +1,13 @@
 /* annotations_deprecated.c generated by valac, the Vala compiler
  * generated from annotations_deprecated.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <string.h>
diff --git a/tests/annotations/description.c-expected b/tests/annotations/description.c-expected
index d6527b7e8b9f8fc6..82ff04ad567c3c44 100644
--- a/tests/annotations/description.c-expected
+++ b/tests/annotations/description.c-expected
@@ -1,6 +1,13 @@
 /* annotations_description.c generated by valac, the Vala compiler
  * generated from annotations_description.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/arrays/cast-struct-boxed-element-access.c-expected b/tests/arrays/cast-struct-boxed-element-access.c-expected
index 82e734768a99efe7..043d5c4b9dcd2959 100644
--- a/tests/arrays/cast-struct-boxed-element-access.c-expected
+++ b/tests/arrays/cast-struct-boxed-element-access.c-expected
@@ -1,6 +1,13 @@
 /* arrays_cast_struct_boxed_element_access.c generated by valac, the Vala compiler
  * generated from arrays_cast_struct_boxed_element_access.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/arrays/class-field-fixed-length-initializer.c-expected b/tests/arrays/class-field-fixed-length-initializer.c-expected
index 4b402f912d089142..2119a785373487d3 100644
--- a/tests/arrays/class-field-fixed-length-initializer.c-expected
+++ b/tests/arrays/class-field-fixed-length-initializer.c-expected
@@ -1,6 +1,13 @@
 /* arrays_class_field_fixed_length_initializer.c generated by valac, the Vala compiler
  * generated from arrays_class_field_fixed_length_initializer.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/arrays/class-field-initializer.c-expected b/tests/arrays/class-field-initializer.c-expected
index 5faddf3db1842b11..08a79041bf68d729 100644
--- a/tests/arrays/class-field-initializer.c-expected
+++ b/tests/arrays/class-field-initializer.c-expected
@@ -1,6 +1,13 @@
 /* arrays_class_field_initializer.c generated by valac, the Vala compiler
  * generated from arrays_class_field_initializer.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/arrays/class-field-length-cname.c-expected b/tests/arrays/class-field-length-cname.c-expected
index 389a0d79a299d829..95a5aadd751c5234 100644
--- a/tests/arrays/class-field-length-cname.c-expected
+++ b/tests/arrays/class-field-length-cname.c-expected
@@ -1,6 +1,13 @@
 /* arrays_class_field_length_cname.c generated by valac, the Vala compiler
  * generated from arrays_class_field_length_cname.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/arrays/constant-element-access.c-expected b/tests/arrays/constant-element-access.c-expected
index 7fd70f27b197652b..bd2fb0f491778dfa 100644
--- a/tests/arrays/constant-element-access.c-expected
+++ b/tests/arrays/constant-element-access.c-expected
@@ -1,6 +1,13 @@
 /* arrays_constant_element_access.c generated by valac, the Vala compiler
  * generated from arrays_constant_element_access.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/arrays/element-class-assignment.c-expected b/tests/arrays/element-class-assignment.c-expected
index 646d0ac077cd8fab..8d2184893fdf95c3 100644
--- a/tests/arrays/element-class-assignment.c-expected
+++ b/tests/arrays/element-class-assignment.c-expected
@@ -1,6 +1,13 @@
 /* arrays_element_class_assignment.c generated by valac, the Vala compiler
  * generated from arrays_element_class_assignment.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
 #include <glib.h>
diff --git a/tests/arrays/element-nullable-assignment.c-expected b/tests/arrays/element-nullable-assignment.c-expected
index ffba74e24aecdc12..8afc97d3a21a607f 100644
--- a/tests/arrays/element-nullable-assignment.c-expected
+++ b/tests/arrays/element-nullable-assignment.c-expected
@@ -1,6 +1,13 @@
 /* arrays_element_nullable_assignment.c generated by valac, the Vala compiler
  * generated from arrays_element_nullable_assignment.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <string.h>
 
diff --git a/tests/arrays/empty-length-0.c-expected b/tests/arrays/empty-length-0.c-expected
index c4d7cbf68257824a..bc70be191cae774b 100644
--- a/tests/arrays/empty-length-0.c-expected
+++ b/tests/arrays/empty-length-0.c-expected
@@ -1,6 +1,13 @@
 /* arrays_empty_length_0.c generated by valac, the Vala compiler
  * generated from arrays_empty_length_0.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/arrays/field-global-length-cname.c-expected b/tests/arrays/field-global-length-cname.c-expected
index 33e3ef1ae9d51e50..f45890c12f874c6e 100644
--- a/tests/arrays/field-global-length-cname.c-expected
+++ b/tests/arrays/field-global-length-cname.c-expected
@@ -1,6 +1,13 @@
 /* arrays_field_global_length_cname.c generated by valac, the Vala compiler
  * generated from arrays_field_global_length_cname.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/arrays/fixed-length-enum-value.c-expected b/tests/arrays/fixed-length-enum-value.c-expected
index 372dcf4ae3ce19be..d82658e7727acaab 100644
--- a/tests/arrays/fixed-length-enum-value.c-expected
+++ b/tests/arrays/fixed-length-enum-value.c-expected
@@ -1,6 +1,13 @@
 /* arrays_fixed_length_enum_value.c generated by valac, the Vala compiler
  * generated from arrays_fixed_length_enum_value.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/arrays/fixed-length-init0-not-allowed.c-expected b/tests/arrays/fixed-length-init0-not-allowed.c-expected
index 4bf72a2f72ff3515..6a304ff2422ec8e4 100644
--- a/tests/arrays/fixed-length-init0-not-allowed.c-expected
+++ b/tests/arrays/fixed-length-init0-not-allowed.c-expected
@@ -1,6 +1,13 @@
 /* arrays_fixed_length_init0_not_allowed.c generated by valac, the Vala compiler
  * generated from arrays_fixed_length_init0_not_allowed.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <string.h>
 
diff --git a/tests/arrays/in-operator-with-boxed-needle.c-expected b/tests/arrays/in-operator-with-boxed-needle.c-expected
index e5c5864b2a4e356e..f7e33ddf0be01cd0 100644
--- a/tests/arrays/in-operator-with-boxed-needle.c-expected
+++ b/tests/arrays/in-operator-with-boxed-needle.c-expected
@@ -1,6 +1,13 @@
 /* arrays_in_operator_with_boxed_needle.c generated by valac, the Vala compiler
  * generated from arrays_in_operator_with_boxed_needle.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <string.h>
 
diff --git a/tests/arrays/inline-namespace-field.c-expected b/tests/arrays/inline-namespace-field.c-expected
index 8a73504cb6cc2746..642f74c724755e32 100644
--- a/tests/arrays/inline-namespace-field.c-expected
+++ b/tests/arrays/inline-namespace-field.c-expected
@@ -1,6 +1,13 @@
 /* arrays_inline_namespace_field.c generated by valac, the Vala compiler
  * generated from arrays_inline_namespace_field.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/arrays/inline-struct.c-expected b/tests/arrays/inline-struct.c-expected
index 7d0e0aa50c23fc24..b19fbe087a22318e 100644
--- a/tests/arrays/inline-struct.c-expected
+++ b/tests/arrays/inline-struct.c-expected
@@ -1,6 +1,13 @@
 /* arrays_inline_struct.c generated by valac, the Vala compiler
  * generated from arrays_inline_struct.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/arrays/length-inline-assignment.c-expected b/tests/arrays/length-inline-assignment.c-expected
index 0255ae4ce741970f..bc446570a8b5d879 100644
--- a/tests/arrays/length-inline-assignment.c-expected
+++ b/tests/arrays/length-inline-assignment.c-expected
@@ -1,6 +1,13 @@
 /* arrays_length_inline_assignment.c generated by valac, the Vala compiler
  * generated from arrays_length_inline_assignment.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #define _vala_assert(expr, msg) if G_LIKELY (expr) ; else g_assertion_message_expr (G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC, msg);
diff --git a/tests/arrays/length-type-include.c-expected b/tests/arrays/length-type-include.c-expected
index a282eecfa2fa4967..8d7d497896ca1442 100644
--- a/tests/arrays/length-type-include.c-expected
+++ b/tests/arrays/length-type-include.c-expected
@@ -1,6 +1,13 @@
 /* arrays_length_type_include.c generated by valac, the Vala compiler
  * generated from arrays_length_type_include.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 static void _vala_main (void);
diff --git a/tests/arrays/length-type.c-expected b/tests/arrays/length-type.c-expected
index 01bb8f7b91868768..85e3ed39ff4dca80 100644
--- a/tests/arrays/length-type.c-expected
+++ b/tests/arrays/length-type.c-expected
@@ -1,6 +1,13 @@
 /* arrays_length_type.c generated by valac, the Vala compiler
  * generated from arrays_length_type.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/arrays/resize-local-size-captured.c-expected b/tests/arrays/resize-local-size-captured.c-expected
index 190b450014a13ed3..ec5ac353c9c4d673 100644
--- a/tests/arrays/resize-local-size-captured.c-expected
+++ b/tests/arrays/resize-local-size-captured.c-expected
@@ -1,6 +1,13 @@
 /* arrays_resize_local_size_captured.c generated by valac, the Vala compiler
  * generated from arrays_resize_local_size_captured.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <string.h>
 
diff --git a/tests/arrays/resize-local-size.c-expected b/tests/arrays/resize-local-size.c-expected
index f3c0464c151c725b..ae323dcbf1af9587 100644
--- a/tests/arrays/resize-local-size.c-expected
+++ b/tests/arrays/resize-local-size.c-expected
@@ -1,6 +1,13 @@
 /* arrays_resize_local_size.c generated by valac, the Vala compiler
  * generated from arrays_resize_local_size.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <string.h>
 
diff --git a/tests/arrays/resize.c-expected b/tests/arrays/resize.c-expected
index 086493fa4494a601..b017feaed790d6d4 100644
--- a/tests/arrays/resize.c-expected
+++ b/tests/arrays/resize.c-expected
@@ -1,6 +1,13 @@
 /* arrays_resize.c generated by valac, the Vala compiler
  * generated from arrays_resize.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/arrays/slice-fixed-length.c-expected b/tests/arrays/slice-fixed-length.c-expected
index 0a6d311260c018a8..02595a315c3cc3a3 100644
--- a/tests/arrays/slice-fixed-length.c-expected
+++ b/tests/arrays/slice-fixed-length.c-expected
@@ -1,6 +1,13 @@
 /* arrays_slice_fixed_length.c generated by valac, the Vala compiler
  * generated from arrays_slice_fixed_length.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/arrays/struct-field-initializer.c-expected b/tests/arrays/struct-field-initializer.c-expected
index 5bf92c2cff7af4f5..bff292d434295dba 100644
--- a/tests/arrays/struct-field-initializer.c-expected
+++ b/tests/arrays/struct-field-initializer.c-expected
@@ -1,6 +1,13 @@
 /* arrays_struct_field_initializer.c generated by valac, the Vala compiler
  * generated from arrays_struct_field_initializer.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/arrays/struct-field-length-cname.c-expected b/tests/arrays/struct-field-length-cname.c-expected
index 3df783b34cdc108e..ea5ba864da773492 100644
--- a/tests/arrays/struct-field-length-cname.c-expected
+++ b/tests/arrays/struct-field-length-cname.c-expected
@@ -1,6 +1,13 @@
 /* arrays_struct_field_length_cname.c generated by valac, the Vala compiler
  * generated from arrays_struct_field_length_cname.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/arrays/struct-initializer-null.c-expected b/tests/arrays/struct-initializer-null.c-expected
index 4de284d9eb026f33..da0a5d296ae8e2a7 100644
--- a/tests/arrays/struct-initializer-null.c-expected
+++ b/tests/arrays/struct-initializer-null.c-expected
@@ -1,6 +1,13 @@
 /* arrays_struct_initializer_null.c generated by valac, the Vala compiler
  * generated from arrays_struct_initializer_null.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/arrays/struct-namespaced-initializer.c-expected b/tests/arrays/struct-namespaced-initializer.c-expected
index 17512a6abe16b4bb..165871dabb6ba04c 100644
--- a/tests/arrays/struct-namespaced-initializer.c-expected
+++ b/tests/arrays/struct-namespaced-initializer.c-expected
@@ -1,6 +1,13 @@
 /* arrays_struct_namespaced_initializer.c generated by valac, the Vala compiler
  * generated from arrays_struct_namespaced_initializer.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/asynchronous/bug595735.c-expected b/tests/asynchronous/bug595735.c-expected
index 3775738475bbec6c..49cfa252b7577cb1 100644
--- a/tests/asynchronous/bug595735.c-expected
+++ b/tests/asynchronous/bug595735.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_bug595735.c generated by valac, the Vala compiler
  * generated from asynchronous_bug595735.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/asynchronous/bug595755.c-expected b/tests/asynchronous/bug595755.c-expected
index 4a3b786c22fd7d6d..c8711eaf396fbf43 100644
--- a/tests/asynchronous/bug595755.c-expected
+++ b/tests/asynchronous/bug595755.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_bug595755.c generated by valac, the Vala compiler
  * generated from asynchronous_bug595755.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/asynchronous/bug596177.c-expected b/tests/asynchronous/bug596177.c-expected
index f80ac45e771506d9..d8120eedf5ee25b5 100644
--- a/tests/asynchronous/bug596177.c-expected
+++ b/tests/asynchronous/bug596177.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_bug596177.c generated by valac, the Vala compiler
  * generated from asynchronous_bug596177.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/asynchronous/bug596861.c-expected b/tests/asynchronous/bug596861.c-expected
index 8139574a9ac64a28..6e837c8983b27c08 100644
--- a/tests/asynchronous/bug596861.c-expected
+++ b/tests/asynchronous/bug596861.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_bug596861.c generated by valac, the Vala compiler
  * generated from asynchronous_bug596861.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <gio/gio.h>
 #include <glib.h>
 
diff --git a/tests/asynchronous/bug597294.c-expected b/tests/asynchronous/bug597294.c-expected
index ee890d6fb86fdf88..bff7052e3c50b0d1 100644
--- a/tests/asynchronous/bug597294.c-expected
+++ b/tests/asynchronous/bug597294.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_bug597294.c generated by valac, the Vala compiler
  * generated from asynchronous_bug597294.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <gio/gio.h>
 
diff --git a/tests/asynchronous/bug598677.c-expected b/tests/asynchronous/bug598677.c-expected
index 9724f6fcf5bcb93b..c9f7a206cf25c09a 100644
--- a/tests/asynchronous/bug598677.c-expected
+++ b/tests/asynchronous/bug598677.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_bug598677.c generated by valac, the Vala compiler
  * generated from asynchronous_bug598677.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/asynchronous/bug598697.c-expected b/tests/asynchronous/bug598697.c-expected
index 028b443c10d30da3..3b3d92379090bba1 100644
--- a/tests/asynchronous/bug598697.c-expected
+++ b/tests/asynchronous/bug598697.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_bug598697.c generated by valac, the Vala compiler
  * generated from asynchronous_bug598697.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gio/gio.h>
diff --git a/tests/asynchronous/bug598698.c-expected b/tests/asynchronous/bug598698.c-expected
index 1fb02af007116994..cf11b4b940e3d91a 100644
--- a/tests/asynchronous/bug598698.c-expected
+++ b/tests/asynchronous/bug598698.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_bug598698.c generated by valac, the Vala compiler
  * generated from asynchronous_bug598698.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/asynchronous/bug599568.c-expected b/tests/asynchronous/bug599568.c-expected
index 8ae3247b5a48bd59..45ac76de24833648 100644
--- a/tests/asynchronous/bug599568.c-expected
+++ b/tests/asynchronous/bug599568.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_bug599568.c generated by valac, the Vala compiler
  * generated from asynchronous_bug599568.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <gio/gio.h>
 #include <glib.h>
 #include <glib-object.h>
diff --git a/tests/asynchronous/bug600827.c-expected b/tests/asynchronous/bug600827.c-expected
index 3e94f402b4691706..1dd996bcacd134d0 100644
--- a/tests/asynchronous/bug600827.c-expected
+++ b/tests/asynchronous/bug600827.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_bug600827.c generated by valac, the Vala compiler
  * generated from asynchronous_bug600827.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/asynchronous/bug601558.c-expected b/tests/asynchronous/bug601558.c-expected
index 081693d164c35c03..924b93ce56c2b28f 100644
--- a/tests/asynchronous/bug601558.c-expected
+++ b/tests/asynchronous/bug601558.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_bug601558.c generated by valac, the Vala compiler
  * generated from asynchronous_bug601558.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/asynchronous/bug602594.c-expected b/tests/asynchronous/bug602594.c-expected
index 0aabc315be93d4dd..211a8299ba5d6b8c 100644
--- a/tests/asynchronous/bug602594.c-expected
+++ b/tests/asynchronous/bug602594.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_bug602594.c generated by valac, the Vala compiler
  * generated from asynchronous_bug602594.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/asynchronous/bug612641.c-expected b/tests/asynchronous/bug612641.c-expected
index 78565ef37a23e3c5..22aa49a74605cae8 100644
--- a/tests/asynchronous/bug612641.c-expected
+++ b/tests/asynchronous/bug612641.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_bug612641.c generated by valac, the Vala compiler
  * generated from asynchronous_bug612641.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gio/gio.h>
diff --git a/tests/asynchronous/bug613484.c-expected b/tests/asynchronous/bug613484.c-expected
index 4ddf9a96272cf02b..047966c794a0d262 100644
--- a/tests/asynchronous/bug613484.c-expected
+++ b/tests/asynchronous/bug613484.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_bug613484.c generated by valac, the Vala compiler
  * generated from asynchronous_bug613484.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/asynchronous/bug614294.c-expected b/tests/asynchronous/bug614294.c-expected
index d92b9a8fe6638004..86d7202622dccd09 100644
--- a/tests/asynchronous/bug614294.c-expected
+++ b/tests/asynchronous/bug614294.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_bug614294.c generated by valac, the Vala compiler
  * generated from asynchronous_bug614294.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/asynchronous/bug620740.c-expected b/tests/asynchronous/bug620740.c-expected
index e6a23ef23db74d95..7549f04bc70a9b3f 100644
--- a/tests/asynchronous/bug620740.c-expected
+++ b/tests/asynchronous/bug620740.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_bug620740.c generated by valac, the Vala compiler
  * generated from asynchronous_bug620740.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/asynchronous/bug626053.c-expected b/tests/asynchronous/bug626053.c-expected
index 6fa949ac1fc02e97..950aedecc218fff0 100644
--- a/tests/asynchronous/bug626053.c-expected
+++ b/tests/asynchronous/bug626053.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_bug626053.c generated by valac, the Vala compiler
  * generated from asynchronous_bug626053.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/asynchronous/bug639591.c-expected b/tests/asynchronous/bug639591.c-expected
index ecc5ec2979d5afd8..440f329d76f14bba 100644
--- a/tests/asynchronous/bug639591.c-expected
+++ b/tests/asynchronous/bug639591.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_bug639591.c generated by valac, the Vala compiler
  * generated from asynchronous_bug639591.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <gio/gio.h>
 
diff --git a/tests/asynchronous/bug640721.c-expected b/tests/asynchronous/bug640721.c-expected
index 3a0427f2879a6471..669b7f006c41b7c5 100644
--- a/tests/asynchronous/bug640721.c-expected
+++ b/tests/asynchronous/bug640721.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_bug640721.c generated by valac, the Vala compiler
  * generated from asynchronous_bug640721.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <gio/gio.h>
 #include <glib.h>
 #include <glib-object.h>
diff --git a/tests/asynchronous/bug641182.c-expected b/tests/asynchronous/bug641182.c-expected
index da0975cc4c5a1261..f2abc2d438bc6def 100644
--- a/tests/asynchronous/bug641182.c-expected
+++ b/tests/asynchronous/bug641182.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_bug641182.c generated by valac, the Vala compiler
  * generated from asynchronous_bug641182.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/asynchronous/bug646945.c-expected b/tests/asynchronous/bug646945.c-expected
index baab03038385e2a6..852c366622cdcd55 100644
--- a/tests/asynchronous/bug646945.c-expected
+++ b/tests/asynchronous/bug646945.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_bug646945.c generated by valac, the Vala compiler
  * generated from asynchronous_bug646945.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 
diff --git a/tests/asynchronous/bug652252.c-expected b/tests/asynchronous/bug652252.c-expected
index a4337dce18cd1a61..e63cc25fc5062b9a 100644
--- a/tests/asynchronous/bug652252.c-expected
+++ b/tests/asynchronous/bug652252.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_bug652252.c generated by valac, the Vala compiler
  * generated from asynchronous_bug652252.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/asynchronous/bug653861.c-expected b/tests/asynchronous/bug653861.c-expected
index 380dfacdfedca947..8eab110e763c525b 100644
--- a/tests/asynchronous/bug653861.c-expected
+++ b/tests/asynchronous/bug653861.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_bug653861.c generated by valac, the Vala compiler
  * generated from asynchronous_bug653861.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/asynchronous/bug654336.c-expected b/tests/asynchronous/bug654336.c-expected
index 71a1e1a4761b34bb..03847733ea6b18f5 100644
--- a/tests/asynchronous/bug654336.c-expected
+++ b/tests/asynchronous/bug654336.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_bug654336.c generated by valac, the Vala compiler
  * generated from asynchronous_bug654336.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <gio/gio.h>
 #include <glib-object.h>
 #include <glib.h>
diff --git a/tests/asynchronous/bug654337.c-expected b/tests/asynchronous/bug654337.c-expected
index 3237071f269723d9..b126e9a7976ad6d1 100644
--- a/tests/asynchronous/bug654337.c-expected
+++ b/tests/asynchronous/bug654337.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_bug654337.c generated by valac, the Vala compiler
  * generated from asynchronous_bug654337.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <gio/gio.h>
 #include <glib-object.h>
 #include <glib.h>
diff --git a/tests/asynchronous/bug659886.c-expected b/tests/asynchronous/bug659886.c-expected
index 75de1ed66853c1b4..c5b2410f45117fc7 100644
--- a/tests/asynchronous/bug659886.c-expected
+++ b/tests/asynchronous/bug659886.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_bug659886.c generated by valac, the Vala compiler
  * generated from asynchronous_bug659886.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 
diff --git a/tests/asynchronous/bug661961.c-expected b/tests/asynchronous/bug661961.c-expected
index c6f8da66481c847a..908d2c1b2b5f0307 100644
--- a/tests/asynchronous/bug661961.c-expected
+++ b/tests/asynchronous/bug661961.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_bug661961.c generated by valac, the Vala compiler
  * generated from asynchronous_bug661961.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <gio/gio.h>
 #include <glib-object.h>
 #include <glib.h>
diff --git a/tests/asynchronous/bug710103.c-expected b/tests/asynchronous/bug710103.c-expected
index 0913a72b6b526c45..b072d3b75414b8b7 100644
--- a/tests/asynchronous/bug710103.c-expected
+++ b/tests/asynchronous/bug710103.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_bug710103.c generated by valac, the Vala compiler
  * generated from asynchronous_bug710103.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <gio/gio.h>
 #include <glib.h>
 #include <glib-object.h>
diff --git a/tests/asynchronous/bug741929.c-expected b/tests/asynchronous/bug741929.c-expected
index 57ed28780d36f1b4..432dc2b4a1f23161 100644
--- a/tests/asynchronous/bug741929.c-expected
+++ b/tests/asynchronous/bug741929.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_bug741929.c generated by valac, the Vala compiler
  * generated from asynchronous_bug741929.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gio/gio.h>
diff --git a/tests/asynchronous/bug742621.c-expected b/tests/asynchronous/bug742621.c-expected
index 093e6c43d80b91ae..7f5e7643abf0b904 100644
--- a/tests/asynchronous/bug742621.c-expected
+++ b/tests/asynchronous/bug742621.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_bug742621.c generated by valac, the Vala compiler
  * generated from asynchronous_bug742621.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gio/gio.h>
diff --git a/tests/asynchronous/bug762819.c-expected b/tests/asynchronous/bug762819.c-expected
index ffb97eca08f4547e..62112ca223c6168d 100644
--- a/tests/asynchronous/bug762819.c-expected
+++ b/tests/asynchronous/bug762819.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_bug762819.c generated by valac, the Vala compiler
  * generated from asynchronous_bug762819.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <stdlib.h>
diff --git a/tests/asynchronous/bug777242.c-expected b/tests/asynchronous/bug777242.c-expected
index 1bfa9d03181b26ee..80808bfd3a7ae988 100644
--- a/tests/asynchronous/bug777242.c-expected
+++ b/tests/asynchronous/bug777242.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_bug777242.c generated by valac, the Vala compiler
  * generated from asynchronous_bug777242.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <gio/gio.h>
 #include <stdlib.h>
diff --git a/tests/asynchronous/bug783543.c-expected b/tests/asynchronous/bug783543.c-expected
index 9d3542f6329d292c..0ff260f53d190db8 100644
--- a/tests/asynchronous/bug783543.c-expected
+++ b/tests/asynchronous/bug783543.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_bug783543.c generated by valac, the Vala compiler
  * generated from asynchronous_bug783543.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/asynchronous/bug792660.c-expected b/tests/asynchronous/bug792660.c-expected
index 20c76608d449cc88..ced2eb52249d0113 100644
--- a/tests/asynchronous/bug792660.c-expected
+++ b/tests/asynchronous/bug792660.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_bug792660.c generated by valac, the Vala compiler
  * generated from asynchronous_bug792660.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <stdlib.h>
diff --git a/tests/asynchronous/bug792942.c-expected b/tests/asynchronous/bug792942.c-expected
index 841d2cf0bda65e4a..f93fb7370f0cf2a8 100644
--- a/tests/asynchronous/bug792942.c-expected
+++ b/tests/asynchronous/bug792942.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_bug792942.c generated by valac, the Vala compiler
  * generated from asynchronous_bug792942.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/asynchronous/bug793158.c-expected b/tests/asynchronous/bug793158.c-expected
index 242de48dccf6123c..a333a6182904b72d 100644
--- a/tests/asynchronous/bug793158.c-expected
+++ b/tests/asynchronous/bug793158.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_bug793158.c generated by valac, the Vala compiler
  * generated from asynchronous_bug793158.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gio/gio.h>
diff --git a/tests/asynchronous/captured-fixed-array.c-expected b/tests/asynchronous/captured-fixed-array.c-expected
index 9d6faa29903a43f3..02c5748a4493b4aa 100644
--- a/tests/asynchronous/captured-fixed-array.c-expected
+++ b/tests/asynchronous/captured-fixed-array.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_captured_fixed_array.c generated by valac, the Vala compiler
  * generated from asynchronous_captured_fixed_array.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <gio/gio.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/asynchronous/catch-error-scope.c-expected b/tests/asynchronous/catch-error-scope.c-expected
index c4d055f0c484c891..4ad323b66bf6f561 100644
--- a/tests/asynchronous/catch-error-scope.c-expected
+++ b/tests/asynchronous/catch-error-scope.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_catch_error_scope.c generated by valac, the Vala compiler
  * generated from asynchronous_catch_error_scope.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gio/gio.h>
diff --git a/tests/asynchronous/catch-in-finally.c-expected b/tests/asynchronous/catch-in-finally.c-expected
index 996c154ae605e2db..b5437a0d3e212f47 100644
--- a/tests/asynchronous/catch-in-finally.c-expected
+++ b/tests/asynchronous/catch-in-finally.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_catch_in_finally.c generated by valac, the Vala compiler
  * generated from asynchronous_catch_in_finally.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gio/gio.h>
diff --git a/tests/asynchronous/closures.c-expected b/tests/asynchronous/closures.c-expected
index 9c2d0f92c09ede53..84f34fbaced4e173 100644
--- a/tests/asynchronous/closures.c-expected
+++ b/tests/asynchronous/closures.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_closures.c generated by valac, the Vala compiler
  * generated from asynchronous_closures.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <gio/gio.h>
 #include <stdlib.h>
diff --git a/tests/asynchronous/constructor-argument-check.c-expected b/tests/asynchronous/constructor-argument-check.c-expected
index 76d364bb0669b58a..8fd489600c0e5ca1 100644
--- a/tests/asynchronous/constructor-argument-check.c-expected
+++ b/tests/asynchronous/constructor-argument-check.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_constructor_argument_check.c generated by valac, the Vala compiler
  * generated from asynchronous_constructor_argument_check.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <stdlib.h>
diff --git a/tests/asynchronous/finish-name.c-expected b/tests/asynchronous/finish-name.c-expected
index e12dcc9b91d284e3..176feb9c5b9c7bb2 100644
--- a/tests/asynchronous/finish-name.c-expected
+++ b/tests/asynchronous/finish-name.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_finish_name.c generated by valac, the Vala compiler
  * generated from asynchronous_finish_name.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <stdlib.h>
diff --git a/tests/asynchronous/generator.c-expected b/tests/asynchronous/generator.c-expected
index 56db316e605327f2..31aad63aef88793f 100644
--- a/tests/asynchronous/generator.c-expected
+++ b/tests/asynchronous/generator.c-expected
@@ -4,6 +4,12 @@
 /* This is based on Luca Bruno's Generator. It illustrates using async methods*/
 /* to emulate a generator style of iterator coding. Note that this runs fine*/
 /* without a main loop.*/
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
 
 #include <glib-object.h>
 #include <gio/gio.h>
diff --git a/tests/asynchronous/main-block-async-call.c-expected b/tests/asynchronous/main-block-async-call.c-expected
index 4eae9bfdc5f27ef7..773b0613f5352313 100644
--- a/tests/asynchronous/main-block-async-call.c-expected
+++ b/tests/asynchronous/main-block-async-call.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_main_block_async_call.c generated by valac, the Vala compiler
  * generated from asynchronous_main_block_async_call.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <gio/gio.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/asynchronous/main-block-async-creation.c-expected b/tests/asynchronous/main-block-async-creation.c-expected
index f84673cd4bd7c907..3b6bc307fc95ae50 100644
--- a/tests/asynchronous/main-block-async-creation.c-expected
+++ b/tests/asynchronous/main-block-async-creation.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_main_block_async_creation.c generated by valac, the Vala compiler
  * generated from asynchronous_main_block_async_creation.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/asynchronous/main-block-async-yield.c-expected b/tests/asynchronous/main-block-async-yield.c-expected
index 99419124399fe233..d9e6a25fcaef268f 100644
--- a/tests/asynchronous/main-block-async-yield.c-expected
+++ b/tests/asynchronous/main-block-async-yield.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_main_block_async_yield.c generated by valac, the Vala compiler
  * generated from asynchronous_main_block_async_yield.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <gio/gio.h>
 #include <glib.h>
 
diff --git a/tests/asynchronous/method-main-async-void.c-expected b/tests/asynchronous/method-main-async-void.c-expected
index c0733f84eaf58721..d39b21aadeffdbf3 100644
--- a/tests/asynchronous/method-main-async-void.c-expected
+++ b/tests/asynchronous/method-main-async-void.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_method_main_async_void.c generated by valac, the Vala compiler
  * generated from asynchronous_method_main_async_void.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <gio/gio.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/asynchronous/method-main-async.c-expected b/tests/asynchronous/method-main-async.c-expected
index e8148c4dcd18e96a..29b6e8771293e10e 100644
--- a/tests/asynchronous/method-main-async.c-expected
+++ b/tests/asynchronous/method-main-async.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_method_main_async.c generated by valac, the Vala compiler
  * generated from asynchronous_method_main_async.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <gio/gio.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/asynchronous/nowrapper.c-expected b/tests/asynchronous/nowrapper.c-expected
index 2424afda6bc52c6e..ec43fc70ba793364 100644
--- a/tests/asynchronous/nowrapper.c-expected
+++ b/tests/asynchronous/nowrapper.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_nowrapper.c generated by valac, the Vala compiler
  * generated from asynchronous_nowrapper.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/asynchronous/out-parameter-free-on-error.c-expected b/tests/asynchronous/out-parameter-free-on-error.c-expected
index de41c609ee59efb8..0f071af1bd8bc840 100644
--- a/tests/asynchronous/out-parameter-free-on-error.c-expected
+++ b/tests/asynchronous/out-parameter-free-on-error.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_out_parameter_free_on_error.c generated by valac, the Vala compiler
  * generated from asynchronous_out_parameter_free_on_error.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gio/gio.h>
diff --git a/tests/asynchronous/result-pos.c-expected b/tests/asynchronous/result-pos.c-expected
index 0875b0cd8cc5bf91..a0abfc6965ce463e 100644
--- a/tests/asynchronous/result-pos.c-expected
+++ b/tests/asynchronous/result-pos.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_result_pos.c generated by valac, the Vala compiler
  * generated from asynchronous_result_pos.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <gio/gio.h>
 #include <glib.h>
 #include <glib-object.h>
diff --git a/tests/asynchronous/yield.c-expected b/tests/asynchronous/yield.c-expected
index 993fdbc33a43387a..29be8e525414c0a5 100644
--- a/tests/asynchronous/yield.c-expected
+++ b/tests/asynchronous/yield.c-expected
@@ -1,6 +1,13 @@
 /* asynchronous_yield.c generated by valac, the Vala compiler
  * generated from asynchronous_yield.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <gio/gio.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/basic-types/array-uint8-uchar-compat.c-expected b/tests/basic-types/array-uint8-uchar-compat.c-expected
index 17cf9aed704e5fb6..78e0610a2370aa53 100644
--- a/tests/basic-types/array-uint8-uchar-compat.c-expected
+++ b/tests/basic-types/array-uint8-uchar-compat.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_array_uint8_uchar_compat.c generated by valac, the Vala compiler
  * generated from basic_types_array_uint8_uchar_compat.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/basic-types/arrays-fixed-assignment.c-expected b/tests/basic-types/arrays-fixed-assignment.c-expected
index fac6d616f8847ff4..029b9dbd9c192d04 100644
--- a/tests/basic-types/arrays-fixed-assignment.c-expected
+++ b/tests/basic-types/arrays-fixed-assignment.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_arrays_fixed_assignment.c generated by valac, the Vala compiler
  * generated from basic_types_arrays_fixed_assignment.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/basic-types/arrays-generics.c-expected b/tests/basic-types/arrays-generics.c-expected
index 01da8c6d53972922..9574e6184fe0e844 100644
--- a/tests/basic-types/arrays-generics.c-expected
+++ b/tests/basic-types/arrays-generics.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_arrays_generics.c generated by valac, the Vala compiler
  * generated from basic_types_arrays_generics.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/basic-types/arrays.c-expected b/tests/basic-types/arrays.c-expected
index 5c4a167092470270..f10f504f0214c038 100644
--- a/tests/basic-types/arrays.c-expected
+++ b/tests/basic-types/arrays.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_arrays.c generated by valac, the Vala compiler
  * generated from basic_types_arrays.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <string.h>
 #include <stdlib.h>
diff --git a/tests/basic-types/boolean-literal.c-expected b/tests/basic-types/boolean-literal.c-expected
index 89441a6c1c12934d..c17b280fa1c515ee 100644
--- a/tests/basic-types/boolean-literal.c-expected
+++ b/tests/basic-types/boolean-literal.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_boolean_literal.c generated by valac, the Vala compiler
  * generated from basic_types_boolean_literal.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 static void _vala_main (void);
diff --git a/tests/basic-types/boolean.c-expected b/tests/basic-types/boolean.c-expected
index 75de4a5bd295eb2c..a4c0cd7b0fd191ad 100644
--- a/tests/basic-types/boolean.c-expected
+++ b/tests/basic-types/boolean.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_boolean.c generated by valac, the Vala compiler
  * generated from basic_types_boolean.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdbool.h>
 #include <glib.h>
 
diff --git a/tests/basic-types/bug571486.c-expected b/tests/basic-types/bug571486.c-expected
index 9949111772bef60a..511d35d746118784 100644
--- a/tests/basic-types/bug571486.c-expected
+++ b/tests/basic-types/bug571486.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_bug571486.c generated by valac, the Vala compiler
  * generated from basic_types_bug571486.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/basic-types/bug591552.c-expected b/tests/basic-types/bug591552.c-expected
index a61a51c7ac2fa429..035e93205a892f49 100644
--- a/tests/basic-types/bug591552.c-expected
+++ b/tests/basic-types/bug591552.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_bug591552.c generated by valac, the Vala compiler
  * generated from basic_types_bug591552.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <string.h>
 
diff --git a/tests/basic-types/bug595751.c-expected b/tests/basic-types/bug595751.c-expected
index 7f02e18714c4b256..b41fded168e4adac 100644
--- a/tests/basic-types/bug595751.c-expected
+++ b/tests/basic-types/bug595751.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_bug595751.c generated by valac, the Vala compiler
  * generated from basic_types_bug595751.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 static void _vala_main (void);
diff --git a/tests/basic-types/bug596637.c-expected b/tests/basic-types/bug596637.c-expected
index 2bdb6d02c56d6c88..98790eecbc811a4f 100644
--- a/tests/basic-types/bug596637.c-expected
+++ b/tests/basic-types/bug596637.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_bug596637.c generated by valac, the Vala compiler
  * generated from basic_types_bug596637.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #define _vala_assert(expr, msg) if G_LIKELY (expr) ; else g_assertion_message_expr (G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC, msg);
diff --git a/tests/basic-types/bug596785.c-expected b/tests/basic-types/bug596785.c-expected
index f950f5325805270d..166202aa2435608b 100644
--- a/tests/basic-types/bug596785.c-expected
+++ b/tests/basic-types/bug596785.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_bug596785.c generated by valac, the Vala compiler
  * generated from basic_types_bug596785.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #define _vala_assert(expr, msg) if G_LIKELY (expr) ; else g_assertion_message_expr (G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC, msg);
diff --git a/tests/basic-types/bug604371.c-expected b/tests/basic-types/bug604371.c-expected
index 3f1ee88b5a6ec9ac..7ca767618d05ee36 100644
--- a/tests/basic-types/bug604371.c-expected
+++ b/tests/basic-types/bug604371.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_bug604371.c generated by valac, the Vala compiler
  * generated from basic_types_bug604371.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/basic-types/bug610660.c-expected b/tests/basic-types/bug610660.c-expected
index 164232e75a6f6ef2..df7e15d0a646816c 100644
--- a/tests/basic-types/bug610660.c-expected
+++ b/tests/basic-types/bug610660.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_bug610660.c generated by valac, the Vala compiler
  * generated from basic_types_bug610660.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <float.h>
 #include <math.h>
diff --git a/tests/basic-types/bug622178.c-expected b/tests/basic-types/bug622178.c-expected
index a8b9cefedc120286..4e0e9b289f86f94b 100644
--- a/tests/basic-types/bug622178.c-expected
+++ b/tests/basic-types/bug622178.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_bug622178.c generated by valac, the Vala compiler
  * generated from basic_types_bug622178.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/basic-types/bug632322.c-expected b/tests/basic-types/bug632322.c-expected
index 5fba8e5db1506d3a..21a6a3f90d432329 100644
--- a/tests/basic-types/bug632322.c-expected
+++ b/tests/basic-types/bug632322.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_bug632322.c generated by valac, the Vala compiler
  * generated from basic_types_bug632322.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #define _vala_assert(expr, msg) if G_LIKELY (expr) ; else g_assertion_message_expr (G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC, msg);
diff --git a/tests/basic-types/bug643612.c-expected b/tests/basic-types/bug643612.c-expected
index e6312a702a0f1088..84811096861069c0 100644
--- a/tests/basic-types/bug643612.c-expected
+++ b/tests/basic-types/bug643612.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_bug643612.c generated by valac, the Vala compiler
  * generated from basic_types_bug643612.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #define _vala_assert(expr, msg) if G_LIKELY (expr) ; else g_assertion_message_expr (G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC, msg);
diff --git a/tests/basic-types/bug644046.c-expected b/tests/basic-types/bug644046.c-expected
index 21672aab2e324c6b..ffeb68325e4488f9 100644
--- a/tests/basic-types/bug644046.c-expected
+++ b/tests/basic-types/bug644046.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_bug644046.c generated by valac, the Vala compiler
  * generated from basic_types_bug644046.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <string.h>
 
diff --git a/tests/basic-types/bug647222.c-expected b/tests/basic-types/bug647222.c-expected
index ac7a23a329178cf8..6b98039a7758f5cd 100644
--- a/tests/basic-types/bug647222.c-expected
+++ b/tests/basic-types/bug647222.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_bug647222.c generated by valac, the Vala compiler
  * generated from basic_types_bug647222.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/basic-types/bug648364.c-expected b/tests/basic-types/bug648364.c-expected
index 69d7e181f75ce1d9..7424c0e8b364ae3f 100644
--- a/tests/basic-types/bug648364.c-expected
+++ b/tests/basic-types/bug648364.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_bug648364.c generated by valac, the Vala compiler
  * generated from basic_types_bug648364.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <string.h>
 
diff --git a/tests/basic-types/bug650993.c-expected b/tests/basic-types/bug650993.c-expected
index 52b5df15f8c8ac61..fabaf909b2829343 100644
--- a/tests/basic-types/bug650993.c-expected
+++ b/tests/basic-types/bug650993.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_bug650993.c generated by valac, the Vala compiler
  * generated from basic_types_bug650993.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/basic-types/bug652380.c-expected b/tests/basic-types/bug652380.c-expected
index 00e5740f61e9c7d0..8d88fced1d489949 100644
--- a/tests/basic-types/bug652380.c-expected
+++ b/tests/basic-types/bug652380.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_bug652380.c generated by valac, the Vala compiler
  * generated from basic_types_bug652380.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <string.h>
 
diff --git a/tests/basic-types/bug655908.c-expected b/tests/basic-types/bug655908.c-expected
index cc8d61546dbe5708..7181bc6712f9d476 100644
--- a/tests/basic-types/bug655908.c-expected
+++ b/tests/basic-types/bug655908.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_bug655908.c generated by valac, the Vala compiler
  * generated from basic_types_bug655908.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <string.h>
 
diff --git a/tests/basic-types/bug659975.c-expected b/tests/basic-types/bug659975.c-expected
index 27c3250ec375a094..7aad1c4f92235245 100644
--- a/tests/basic-types/bug659975.c-expected
+++ b/tests/basic-types/bug659975.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_bug659975.c generated by valac, the Vala compiler
  * generated from basic_types_bug659975.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/basic-types/bug678791.c-expected b/tests/basic-types/bug678791.c-expected
index 9826ce745e2f7e55..e4b69e82f9ad717b 100644
--- a/tests/basic-types/bug678791.c-expected
+++ b/tests/basic-types/bug678791.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_bug678791.c generated by valac, the Vala compiler
  * generated from basic_types_bug678791.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/basic-types/bug686336.c-expected b/tests/basic-types/bug686336.c-expected
index f485d7871b3ddeea..31bccc3249924e9e 100644
--- a/tests/basic-types/bug686336.c-expected
+++ b/tests/basic-types/bug686336.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_bug686336.c generated by valac, the Vala compiler
  * generated from basic_types_bug686336.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/basic-types/bug729907.c-expected b/tests/basic-types/bug729907.c-expected
index efe52397a878da3d..fa91f28fa1fe434d 100644
--- a/tests/basic-types/bug729907.c-expected
+++ b/tests/basic-types/bug729907.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_bug729907.c generated by valac, the Vala compiler
  * generated from basic_types_bug729907.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #define _vala_assert(expr, msg) if G_LIKELY (expr) ; else g_assertion_message_expr (G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC, msg);
diff --git a/tests/basic-types/bug731017.c-expected b/tests/basic-types/bug731017.c-expected
index 5de4afa6feed980e..cfc5e7c7ef153fb4 100644
--- a/tests/basic-types/bug731017.c-expected
+++ b/tests/basic-types/bug731017.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_bug731017.c generated by valac, the Vala compiler
  * generated from basic_types_bug731017.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/basic-types/bug756376.c-expected b/tests/basic-types/bug756376.c-expected
index 773d6921ce50f4f3..2d06e801f86a7504 100644
--- a/tests/basic-types/bug756376.c-expected
+++ b/tests/basic-types/bug756376.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_bug756376.c generated by valac, the Vala compiler
  * generated from basic_types_bug756376.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #define FOO_BAR 5
diff --git a/tests/basic-types/bug761307.c-expected b/tests/basic-types/bug761307.c-expected
index 8fe2e99626de3a75..5292df9ee60237d4 100644
--- a/tests/basic-types/bug761307.c-expected
+++ b/tests/basic-types/bug761307.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_bug761307.c generated by valac, the Vala compiler
  * generated from basic_types_bug761307.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/basic-types/bug761736.c-expected b/tests/basic-types/bug761736.c-expected
index 1a2ecb8b4e99daf4..1a77d93a68221008 100644
--- a/tests/basic-types/bug761736.c-expected
+++ b/tests/basic-types/bug761736.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_bug761736.c generated by valac, the Vala compiler
  * generated from basic_types_bug761736.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/basic-types/bug772426.c-expected b/tests/basic-types/bug772426.c-expected
index 07c92c0d1dfe89e2..66f2e578de9cd451 100644
--- a/tests/basic-types/bug772426.c-expected
+++ b/tests/basic-types/bug772426.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_bug772426.c generated by valac, the Vala compiler
  * generated from basic_types_bug772426.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <string.h>
 
diff --git a/tests/basic-types/bug787152.c-expected b/tests/basic-types/bug787152.c-expected
index f06e3ddbbae26118..daf58bffb348afc9 100644
--- a/tests/basic-types/bug787152.c-expected
+++ b/tests/basic-types/bug787152.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_bug787152.c generated by valac, the Vala compiler
  * generated from basic_types_bug787152.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <string.h>
 
diff --git a/tests/basic-types/bug788775.c-expected b/tests/basic-types/bug788775.c-expected
index f0f5c33b6bdbfb08..9f8ccce4946338bb 100644
--- a/tests/basic-types/bug788775.c-expected
+++ b/tests/basic-types/bug788775.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_bug788775.c generated by valac, the Vala compiler
  * generated from basic_types_bug788775.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/basic-types/custom-types.c-expected b/tests/basic-types/custom-types.c-expected
index 2e053ab4ea002711..d5ceb6f0f14bcf58 100644
--- a/tests/basic-types/custom-types.c-expected
+++ b/tests/basic-types/custom-types.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_custom_types.c generated by valac, the Vala compiler
  * generated from basic_types_custom_types.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdint.h>
 #include <stdbool.h>
 #include <glib.h>
diff --git a/tests/basic-types/default-gtype.c-expected b/tests/basic-types/default-gtype.c-expected
index 2d99e950ad2e5cdd..f984c6a54300c5f7 100644
--- a/tests/basic-types/default-gtype.c-expected
+++ b/tests/basic-types/default-gtype.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_default_gtype.c generated by valac, the Vala compiler
  * generated from basic_types_default_gtype.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/basic-types/escape-chars.c-expected b/tests/basic-types/escape-chars.c-expected
index 2bb8e148d89bf286..c18f9fb8526b6945 100644
--- a/tests/basic-types/escape-chars.c-expected
+++ b/tests/basic-types/escape-chars.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_escape_chars.c generated by valac, the Vala compiler
  * generated from basic_types_escape_chars.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/basic-types/float-literals.c-expected b/tests/basic-types/float-literals.c-expected
index 2447e3e680f66840..1950d1a7930756b3 100644
--- a/tests/basic-types/float-literals.c-expected
+++ b/tests/basic-types/float-literals.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_float_literals.c generated by valac, the Vala compiler
  * generated from basic_types_float_literals.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <float.h>
 #include <math.h>
diff --git a/tests/basic-types/floats-boxed-cast.c-expected b/tests/basic-types/floats-boxed-cast.c-expected
index b5d331fd05812ebd..c3a66c4ebfa76837 100644
--- a/tests/basic-types/floats-boxed-cast.c-expected
+++ b/tests/basic-types/floats-boxed-cast.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_floats_boxed_cast.c generated by valac, the Vala compiler
  * generated from basic_types_floats_boxed_cast.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <float.h>
 #include <math.h>
diff --git a/tests/basic-types/floats.c-expected b/tests/basic-types/floats.c-expected
index 5d66d89398da46cb..e115afb9341b532d 100644
--- a/tests/basic-types/floats.c-expected
+++ b/tests/basic-types/floats.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_floats.c generated by valac, the Vala compiler
  * generated from basic_types_floats.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <float.h>
 #include <math.h>
diff --git a/tests/basic-types/garray.c-expected b/tests/basic-types/garray.c-expected
index 6365624182f204c5..184abb9a8591849c 100644
--- a/tests/basic-types/garray.c-expected
+++ b/tests/basic-types/garray.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_garray.c generated by valac, the Vala compiler
  * generated from basic_types_garray.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/basic-types/gassert.c-expected b/tests/basic-types/gassert.c-expected
index f73315a56b63e6bc..9a70a1b989a8c2ad 100644
--- a/tests/basic-types/gassert.c-expected
+++ b/tests/basic-types/gassert.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_gassert.c generated by valac, the Vala compiler
  * generated from basic_types_gassert.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <float.h>
 #include <math.h>
diff --git a/tests/basic-types/glists.c-expected b/tests/basic-types/glists.c-expected
index 4f3763c60d366cd7..ef49b4f5d04e2ac7 100644
--- a/tests/basic-types/glists.c-expected
+++ b/tests/basic-types/glists.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_glists.c generated by valac, the Vala compiler
  * generated from basic_types_glists.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/basic-types/glists_remove.c-expected b/tests/basic-types/glists_remove.c-expected
index f8407854bbcf64e9..bb07a1bd44fdca43 100644
--- a/tests/basic-types/glists_remove.c-expected
+++ b/tests/basic-types/glists_remove.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_glists_remove.c generated by valac, the Vala compiler
  * generated from basic_types_glists_remove.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/basic-types/gptrarray.c-expected b/tests/basic-types/gptrarray.c-expected
index 73dd27e3b6bcf0eb..d1c47981674c1519 100644
--- a/tests/basic-types/gptrarray.c-expected
+++ b/tests/basic-types/gptrarray.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_gptrarray.c generated by valac, the Vala compiler
  * generated from basic_types_gptrarray.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/basic-types/gvariants-unboxing-safe.c-expected b/tests/basic-types/gvariants-unboxing-safe.c-expected
index 2c8c4e8a4dd4a2b6..09104081e98feff2 100644
--- a/tests/basic-types/gvariants-unboxing-safe.c-expected
+++ b/tests/basic-types/gvariants-unboxing-safe.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_gvariants_unboxing_safe.c generated by valac, the Vala compiler
  * generated from basic_types_gvariants_unboxing_safe.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/basic-types/gvariants.c-expected b/tests/basic-types/gvariants.c-expected
index 8d4cfdd799daef04..597055688a994def 100644
--- a/tests/basic-types/gvariants.c-expected
+++ b/tests/basic-types/gvariants.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_gvariants.c generated by valac, the Vala compiler
  * generated from basic_types_gvariants.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/basic-types/integer-literals.c-expected b/tests/basic-types/integer-literals.c-expected
index c534fbe7f03b1934..bde653fc6f6f0db3 100644
--- a/tests/basic-types/integer-literals.c-expected
+++ b/tests/basic-types/integer-literals.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_integer_literals.c generated by valac, the Vala compiler
  * generated from basic_types_integer_literals.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 static void _vala_main (void);
diff --git a/tests/basic-types/integers-boxed-cast.c-expected b/tests/basic-types/integers-boxed-cast.c-expected
index e13d9a94d0bfb741..2c776da9b57fca0e 100644
--- a/tests/basic-types/integers-boxed-cast.c-expected
+++ b/tests/basic-types/integers-boxed-cast.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_integers_boxed_cast.c generated by valac, the Vala compiler
  * generated from basic_types_integers_boxed_cast.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <string.h>
 
diff --git a/tests/basic-types/integers.c-expected b/tests/basic-types/integers.c-expected
index cdad296a0a7b0bb7..c7f74d1071dad604 100644
--- a/tests/basic-types/integers.c-expected
+++ b/tests/basic-types/integers.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_integers.c generated by valac, the Vala compiler
  * generated from basic_types_integers.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/basic-types/null.c-expected b/tests/basic-types/null.c-expected
index 8aaf78b18e1cee04..478f2be8ddce4721 100644
--- a/tests/basic-types/null.c-expected
+++ b/tests/basic-types/null.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_null.c generated by valac, the Vala compiler
  * generated from basic_types_null.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 static void _vala_main (void);
diff --git a/tests/basic-types/pointers-arithmetic.c-expected b/tests/basic-types/pointers-arithmetic.c-expected
index 848f092a438196bf..fdb256c5b727003e 100644
--- a/tests/basic-types/pointers-arithmetic.c-expected
+++ b/tests/basic-types/pointers-arithmetic.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_pointers_arithmetic.c generated by valac, the Vala compiler
  * generated from basic_types_pointers_arithmetic.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/basic-types/pointers.c-expected b/tests/basic-types/pointers.c-expected
index ed1a1aa5d69c020d..103789cd5a2998d8 100644
--- a/tests/basic-types/pointers.c-expected
+++ b/tests/basic-types/pointers.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_pointers.c generated by valac, the Vala compiler
  * generated from basic_types_pointers.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/basic-types/sizeof.c-expected b/tests/basic-types/sizeof.c-expected
index 1beba725b050d03c..30d01aeb13229e7b 100644
--- a/tests/basic-types/sizeof.c-expected
+++ b/tests/basic-types/sizeof.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_sizeof.c generated by valac, the Vala compiler
  * generated from basic_types_sizeof.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #define simple_size ((gsize) sizeof (gint))
diff --git a/tests/basic-types/string-array-append.c-expected b/tests/basic-types/string-array-append.c-expected
index 222f34faa55d8c91..74ade9562a54cb1e 100644
--- a/tests/basic-types/string-array-append.c-expected
+++ b/tests/basic-types/string-array-append.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_string_array_append.c generated by valac, the Vala compiler
  * generated from basic_types_string_array_append.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/basic-types/string-relation.c-expected b/tests/basic-types/string-relation.c-expected
index 8fcb00f5dfc2402a..043abf188b0be92f 100644
--- a/tests/basic-types/string-relation.c-expected
+++ b/tests/basic-types/string-relation.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_string_relation.c generated by valac, the Vala compiler
  * generated from basic_types_string_relation.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #define _vala_assert(expr, msg) if G_LIKELY (expr) ; else g_assertion_message_expr (G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC, msg);
diff --git a/tests/basic-types/strings.c-expected b/tests/basic-types/strings.c-expected
index d48d7b2805c5e87e..b7b83a1b92d5955c 100644
--- a/tests/basic-types/strings.c-expected
+++ b/tests/basic-types/strings.c-expected
@@ -1,6 +1,13 @@
 /* basic_types_strings.c generated by valac, the Vala compiler
  * generated from basic_types_strings.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/chainup/bug791785.c-expected b/tests/chainup/bug791785.c-expected
index bfc93915145a9ece..9c42b2adfda58dda 100644
--- a/tests/chainup/bug791785.c-expected
+++ b/tests/chainup/bug791785.c-expected
@@ -1,6 +1,13 @@
 /* chainup_bug791785.c generated by valac, the Vala compiler
  * generated from chainup_bug791785.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/chainup/class-base-foo.c-expected b/tests/chainup/class-base-foo.c-expected
index 54766f06d7e04e35..b521f08fa34f99f0 100644
--- a/tests/chainup/class-base-foo.c-expected
+++ b/tests/chainup/class-base-foo.c-expected
@@ -1,6 +1,13 @@
 /* chainup_class_base_foo.c generated by valac, the Vala compiler
  * generated from chainup_class_base_foo.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/chainup/class-base.c-expected b/tests/chainup/class-base.c-expected
index 9752d6f66aa56716..5f6e897368fa7f0a 100644
--- a/tests/chainup/class-base.c-expected
+++ b/tests/chainup/class-base.c-expected
@@ -1,6 +1,13 @@
 /* chainup_class_base.c generated by valac, the Vala compiler
  * generated from chainup_class_base.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/chainup/class-compact-base.c-expected b/tests/chainup/class-compact-base.c-expected
index 519b2e6b6f929e08..e72f25d178aea0c7 100644
--- a/tests/chainup/class-compact-base.c-expected
+++ b/tests/chainup/class-compact-base.c-expected
@@ -1,6 +1,13 @@
 /* chainup_class_compact_base.c generated by valac, the Vala compiler
  * generated from chainup_class_compact_base.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/chainup/class-compact-this.c-expected b/tests/chainup/class-compact-this.c-expected
index aaeb7299e4e2feaa..83de13682123edb0 100644
--- a/tests/chainup/class-compact-this.c-expected
+++ b/tests/chainup/class-compact-this.c-expected
@@ -1,6 +1,13 @@
 /* chainup_class_compact_this.c generated by valac, the Vala compiler
  * generated from chainup_class_compact_this.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/chainup/class-object.c-expected b/tests/chainup/class-object.c-expected
index 9d95ec4c618b5fe6..4c392c8d7be882a2 100644
--- a/tests/chainup/class-object.c-expected
+++ b/tests/chainup/class-object.c-expected
@@ -1,6 +1,13 @@
 /* chainup_class_object.c generated by valac, the Vala compiler
  * generated from chainup_class_object.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/chainup/class-this-foo.c-expected b/tests/chainup/class-this-foo.c-expected
index 3e2de9849c703429..14e8aaa811670dbe 100644
--- a/tests/chainup/class-this-foo.c-expected
+++ b/tests/chainup/class-this-foo.c-expected
@@ -1,6 +1,13 @@
 /* chainup_class_this_foo.c generated by valac, the Vala compiler
  * generated from chainup_class_this_foo.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/chainup/class-this.c-expected b/tests/chainup/class-this.c-expected
index 1fe914c03447d027..8ef7bdcd6a352392 100644
--- a/tests/chainup/class-this.c-expected
+++ b/tests/chainup/class-this.c-expected
@@ -1,6 +1,13 @@
 /* chainup_class_this.c generated by valac, the Vala compiler
  * generated from chainup_class_this.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/chainup/method-lambda-base.c-expected b/tests/chainup/method-lambda-base.c-expected
index cfc1a553f1d4bfd1..eb6e6868bfd1edcb 100644
--- a/tests/chainup/method-lambda-base.c-expected
+++ b/tests/chainup/method-lambda-base.c-expected
@@ -1,6 +1,13 @@
 /* chainup_method_lambda_base.c generated by valac, the Vala compiler
  * generated from chainup_method_lambda_base.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/chainup/no-chainup.c-expected b/tests/chainup/no-chainup.c-expected
index 1791f50843333f9e..f7e3828665face0c 100644
--- a/tests/chainup/no-chainup.c-expected
+++ b/tests/chainup/no-chainup.c-expected
@@ -1,6 +1,13 @@
 /* chainup_no_chainup.c generated by valac, the Vala compiler
  * generated from chainup_no_chainup.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/chainup/signal-default-handler.c-expected b/tests/chainup/signal-default-handler.c-expected
index a4b6f5a7539beecf..bd3f26488ec2072f 100644
--- a/tests/chainup/signal-default-handler.c-expected
+++ b/tests/chainup/signal-default-handler.c-expected
@@ -1,6 +1,13 @@
 /* chainup_signal_default_handler.c generated by valac, the Vala compiler
  * generated from chainup_signal_default_handler.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/chainup/struct-base-foo.c-expected b/tests/chainup/struct-base-foo.c-expected
index 47c39e8d6eac9dfa..36fd436b253aacaa 100644
--- a/tests/chainup/struct-base-foo.c-expected
+++ b/tests/chainup/struct-base-foo.c-expected
@@ -1,6 +1,13 @@
 /* chainup_struct_base_foo.c generated by valac, the Vala compiler
  * generated from chainup_struct_base_foo.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/chainup/struct-base.c-expected b/tests/chainup/struct-base.c-expected
index c9c2fa049e6563b2..3c9a2ecd80f492ba 100644
--- a/tests/chainup/struct-base.c-expected
+++ b/tests/chainup/struct-base.c-expected
@@ -1,6 +1,13 @@
 /* chainup_struct_base.c generated by valac, the Vala compiler
  * generated from chainup_struct_base.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/chainup/struct-no-gtype-base.c-expected b/tests/chainup/struct-no-gtype-base.c-expected
index 1926db7806874732..dbb03377c8f63a6e 100644
--- a/tests/chainup/struct-no-gtype-base.c-expected
+++ b/tests/chainup/struct-no-gtype-base.c-expected
@@ -1,6 +1,13 @@
 /* chainup_struct_no_gtype_base.c generated by valac, the Vala compiler
  * generated from chainup_struct_no_gtype_base.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <string.h>
 
diff --git a/tests/chainup/struct-simple-no-gtype-base.c-expected b/tests/chainup/struct-simple-no-gtype-base.c-expected
index 8ade7ae6e02818ad..8bb3d5806fbbe587 100644
--- a/tests/chainup/struct-simple-no-gtype-base.c-expected
+++ b/tests/chainup/struct-simple-no-gtype-base.c-expected
@@ -1,6 +1,13 @@
 /* chainup_struct_simple_no_gtype_base.c generated by valac, the Vala compiler
  * generated from chainup_struct_simple_no_gtype_base.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdint.h>
 #include <glib.h>
 
diff --git a/tests/chainup/struct-this-foo.c-expected b/tests/chainup/struct-this-foo.c-expected
index cee0a3e9a75a1146..fb907afcd2b8cf46 100644
--- a/tests/chainup/struct-this-foo.c-expected
+++ b/tests/chainup/struct-this-foo.c-expected
@@ -1,6 +1,13 @@
 /* chainup_struct_this_foo.c generated by valac, the Vala compiler
  * generated from chainup_struct_this_foo.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/chainup/struct-this.c-expected b/tests/chainup/struct-this.c-expected
index 4c8ee333600ea995..848a87464920156a 100644
--- a/tests/chainup/struct-this.c-expected
+++ b/tests/chainup/struct-this.c-expected
@@ -1,6 +1,13 @@
 /* chainup_struct_this.c generated by valac, the Vala compiler
  * generated from chainup_struct_this.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/constants/delegate-type.c-expected b/tests/constants/delegate-type.c-expected
index 126728767baffcf2..30dafe0bc97d0f2f 100644
--- a/tests/constants/delegate-type.c-expected
+++ b/tests/constants/delegate-type.c-expected
@@ -1,6 +1,13 @@
 /* constants_delegate_type.c generated by valac, the Vala compiler
  * generated from constants_delegate_type.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/constants/glog.c-expected b/tests/constants/glog.c-expected
index 02322fbd14752cfc..bf36d16447033206 100644
--- a/tests/constants/glog.c-expected
+++ b/tests/constants/glog.c-expected
@@ -1,6 +1,13 @@
 /* constants_glog.c generated by valac, the Vala compiler
  * generated from constants_glog.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/constants/member-access-enum.c-expected b/tests/constants/member-access-enum.c-expected
index 9cea27ce87456cc9..dafbdb635e7ce243 100644
--- a/tests/constants/member-access-enum.c-expected
+++ b/tests/constants/member-access-enum.c-expected
@@ -1,6 +1,13 @@
 /* constants_member_access_enum.c generated by valac, the Vala compiler
  * generated from constants_member_access_enum.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
 #include <glib.h>
diff --git a/tests/constants/member-access.c-expected b/tests/constants/member-access.c-expected
index c120ffd5be4ff0b7..1284b6b108a72316 100644
--- a/tests/constants/member-access.c-expected
+++ b/tests/constants/member-access.c-expected
@@ -1,6 +1,13 @@
 /* constants_member_access.c generated by valac, the Vala compiler
  * generated from constants_member_access.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/constants/strings.c-expected b/tests/constants/strings.c-expected
index f0bb50459c90c303..10cab7405c660d96 100644
--- a/tests/constants/strings.c-expected
+++ b/tests/constants/strings.c-expected
@@ -1,6 +1,13 @@
 /* constants_strings.c generated by valac, the Vala compiler
  * generated from constants_strings.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/control-flow/assigned-local-variable.c-expected b/tests/control-flow/assigned-local-variable.c-expected
index ad1119fae4536550..b3760c0fa25794d6 100644
--- a/tests/control-flow/assigned-local-variable.c-expected
+++ b/tests/control-flow/assigned-local-variable.c-expected
@@ -1,6 +1,13 @@
 /* control_flow_assigned_local_variable.c generated by valac, the Vala compiler
  * generated from control_flow_assigned_local_variable.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/control-flow/break.c-expected b/tests/control-flow/break.c-expected
index a806409b320523f3..2506184813665231 100644
--- a/tests/control-flow/break.c-expected
+++ b/tests/control-flow/break.c-expected
@@ -1,6 +1,13 @@
 /* control_flow_break.c generated by valac, the Vala compiler
  * generated from control_flow_break.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdio.h>
diff --git a/tests/control-flow/bug628336.c-expected b/tests/control-flow/bug628336.c-expected
index 1e5fb82ce2cf7a56..5e55cc709db61a7f 100644
--- a/tests/control-flow/bug628336.c-expected
+++ b/tests/control-flow/bug628336.c-expected
@@ -1,6 +1,13 @@
 /* control_flow_bug628336.c generated by valac, the Vala compiler
  * generated from control_flow_bug628336.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/control-flow/bug639482.c-expected b/tests/control-flow/bug639482.c-expected
index d98351ebc5d4a9d0..9b7dc6eb031c4d2f 100644
--- a/tests/control-flow/bug639482.c-expected
+++ b/tests/control-flow/bug639482.c-expected
@@ -1,6 +1,13 @@
 /* control_flow_bug639482.c generated by valac, the Vala compiler
  * generated from control_flow_bug639482.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/control-flow/bug652549.c-expected b/tests/control-flow/bug652549.c-expected
index 6e0999e7c9fbda24..3501ee090ca23d2b 100644
--- a/tests/control-flow/bug652549.c-expected
+++ b/tests/control-flow/bug652549.c-expected
@@ -1,6 +1,13 @@
 /* control_flow_bug652549.c generated by valac, the Vala compiler
  * generated from control_flow_bug652549.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <string.h>
 
diff --git a/tests/control-flow/bug661985.c-expected b/tests/control-flow/bug661985.c-expected
index 6e81e5156327f95e..eba585c7c12ee4e0 100644
--- a/tests/control-flow/bug661985.c-expected
+++ b/tests/control-flow/bug661985.c-expected
@@ -1,6 +1,13 @@
 /* control_flow_bug661985.c generated by valac, the Vala compiler
  * generated from control_flow_bug661985.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/control-flow/bug665904.c-expected b/tests/control-flow/bug665904.c-expected
index a66522b72d8cff39..90932393eb4f4ae1 100644
--- a/tests/control-flow/bug665904.c-expected
+++ b/tests/control-flow/bug665904.c-expected
@@ -1,6 +1,13 @@
 /* control_flow_bug665904.c generated by valac, the Vala compiler
  * generated from control_flow_bug665904.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <float.h>
 #include <math.h>
diff --git a/tests/control-flow/bug691514.c-expected b/tests/control-flow/bug691514.c-expected
index a9d9a29b1c2d4214..84466919bc34abea 100644
--- a/tests/control-flow/bug691514.c-expected
+++ b/tests/control-flow/bug691514.c-expected
@@ -1,6 +1,13 @@
 /* control_flow_bug691514.c generated by valac, the Vala compiler
  * generated from control_flow_bug691514.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/control-flow/bug736774-1.c-expected b/tests/control-flow/bug736774-1.c-expected
index f687209d92a8f988..36604f91017ec248 100644
--- a/tests/control-flow/bug736774-1.c-expected
+++ b/tests/control-flow/bug736774-1.c-expected
@@ -1,6 +1,13 @@
 /* control_flow_bug736774_1.c generated by valac, the Vala compiler
  * generated from control_flow_bug736774_1.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/control-flow/bug736774-2.c-expected b/tests/control-flow/bug736774-2.c-expected
index b9567e16dc27e928..26fcfe8dde7062d8 100644
--- a/tests/control-flow/bug736774-2.c-expected
+++ b/tests/control-flow/bug736774-2.c-expected
@@ -1,6 +1,13 @@
 /* control_flow_bug736774_2.c generated by valac, the Vala compiler
  * generated from control_flow_bug736774_2.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/control-flow/bug761267-1.c-expected b/tests/control-flow/bug761267-1.c-expected
index fdf7617e906303b4..ff1af4c34286e009 100644
--- a/tests/control-flow/bug761267-1.c-expected
+++ b/tests/control-flow/bug761267-1.c-expected
@@ -1,6 +1,13 @@
 /* control_flow_bug761267_1.c generated by valac, the Vala compiler
  * generated from control_flow_bug761267_1.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/control-flow/bug761267-2.c-expected b/tests/control-flow/bug761267-2.c-expected
index 14476bde57f8a5ab..ef009b4d4d2cdd89 100644
--- a/tests/control-flow/bug761267-2.c-expected
+++ b/tests/control-flow/bug761267-2.c-expected
@@ -1,6 +1,13 @@
 /* control_flow_bug761267_2.c generated by valac, the Vala compiler
  * generated from control_flow_bug761267_2.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/control-flow/bug764440.c-expected b/tests/control-flow/bug764440.c-expected
index 1b5cf751c092d36d..84dbcd1c8ef2e95f 100644
--- a/tests/control-flow/bug764440.c-expected
+++ b/tests/control-flow/bug764440.c-expected
@@ -1,6 +1,13 @@
 /* control_flow_bug764440.c generated by valac, the Vala compiler
  * generated from control_flow_bug764440.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <stdlib.h>
diff --git a/tests/control-flow/coalesce-as-argument.c-expected b/tests/control-flow/coalesce-as-argument.c-expected
index 2ca2a881fba49ed3..e080ffa3a6c139c9 100644
--- a/tests/control-flow/coalesce-as-argument.c-expected
+++ b/tests/control-flow/coalesce-as-argument.c-expected
@@ -1,6 +1,13 @@
 /* control_flow_coalesce_as_argument.c generated by valac, the Vala compiler
  * generated from control_flow_coalesce_as_argument.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/control-flow/coalesce-execution-order.c-expected b/tests/control-flow/coalesce-execution-order.c-expected
index efaf3e11ed364cb8..2c9557b3eeed21ed 100644
--- a/tests/control-flow/coalesce-execution-order.c-expected
+++ b/tests/control-flow/coalesce-execution-order.c-expected
@@ -1,6 +1,13 @@
 /* control_flow_coalesce_execution_order.c generated by valac, the Vala compiler
  * generated from control_flow_coalesce_execution_order.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/control-flow/coalesce-reference-transfer.c-expected b/tests/control-flow/coalesce-reference-transfer.c-expected
index 9a27fcba1a21ac72..940085209e42a5ed 100644
--- a/tests/control-flow/coalesce-reference-transfer.c-expected
+++ b/tests/control-flow/coalesce-reference-transfer.c-expected
@@ -1,6 +1,13 @@
 /* control_flow_coalesce_reference_transfer.c generated by valac, the Vala compiler
  * generated from control_flow_coalesce_reference_transfer.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/control-flow/coalesce-right-value.c-expected b/tests/control-flow/coalesce-right-value.c-expected
index 85fb39c40dbc0a15..05a3dc46b0538c96 100644
--- a/tests/control-flow/coalesce-right-value.c-expected
+++ b/tests/control-flow/coalesce-right-value.c-expected
@@ -1,6 +1,13 @@
 /* control_flow_coalesce_right_value.c generated by valac, the Vala compiler
  * generated from control_flow_coalesce_right_value.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/control-flow/coalesce-short-circuit.c-expected b/tests/control-flow/coalesce-short-circuit.c-expected
index 461a854a03d977e2..5ab485e8a297a427 100644
--- a/tests/control-flow/coalesce-short-circuit.c-expected
+++ b/tests/control-flow/coalesce-short-circuit.c-expected
@@ -1,6 +1,13 @@
 /* control_flow_coalesce_short_circuit.c generated by valac, the Vala compiler
  * generated from control_flow_coalesce_short_circuit.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/control-flow/conditional-as-argument.c-expected b/tests/control-flow/conditional-as-argument.c-expected
index 880af4204bc25db3..1b4e46886c60ea8d 100644
--- a/tests/control-flow/conditional-as-argument.c-expected
+++ b/tests/control-flow/conditional-as-argument.c-expected
@@ -1,6 +1,13 @@
 /* control_flow_conditional_as_argument.c generated by valac, the Vala compiler
  * generated from control_flow_conditional_as_argument.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/control-flow/expressions-conditional.c-expected b/tests/control-flow/expressions-conditional.c-expected
index 0e026d8648fc7049..b89c47cf7729a0c2 100644
--- a/tests/control-flow/expressions-conditional.c-expected
+++ b/tests/control-flow/expressions-conditional.c-expected
@@ -1,6 +1,13 @@
 /* control_flow_expressions_conditional.c generated by valac, the Vala compiler
  * generated from control_flow_expressions_conditional.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/control-flow/finally-no-return.c-expected b/tests/control-flow/finally-no-return.c-expected
index bdbb991c1a92e9dd..c93d2caee9c82360 100644
--- a/tests/control-flow/finally-no-return.c-expected
+++ b/tests/control-flow/finally-no-return.c-expected
@@ -1,6 +1,13 @@
 /* control_flow_finally_no_return.c generated by valac, the Vala compiler
  * generated from control_flow_finally_no_return.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/control-flow/for-switch-continue.c-expected b/tests/control-flow/for-switch-continue.c-expected
index b6a5eeafed934faa..c18a613ed973449c 100644
--- a/tests/control-flow/for-switch-continue.c-expected
+++ b/tests/control-flow/for-switch-continue.c-expected
@@ -1,6 +1,13 @@
 /* control_flow_for_switch_continue.c generated by valac, the Vala compiler
  * generated from control_flow_for_switch_continue.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/control-flow/for.c-expected b/tests/control-flow/for.c-expected
index f873866c40233abb..2fca3fd033a90aba 100644
--- a/tests/control-flow/for.c-expected
+++ b/tests/control-flow/for.c-expected
@@ -1,6 +1,13 @@
 /* control_flow_for.c generated by valac, the Vala compiler
  * generated from control_flow_for.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/control-flow/foreach.c-expected b/tests/control-flow/foreach.c-expected
index 0f9bd45f9d318341..076e1dd26c567626 100644
--- a/tests/control-flow/foreach.c-expected
+++ b/tests/control-flow/foreach.c-expected
@@ -1,6 +1,13 @@
 /* control_flow_foreach.c generated by valac, the Vala compiler
  * generated from control_flow_foreach.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/control-flow/local-clash-with-implicit-this.c-expected b/tests/control-flow/local-clash-with-implicit-this.c-expected
index ea99a1cc2fd3d28f..ecc02ec6058e13a8 100644
--- a/tests/control-flow/local-clash-with-implicit-this.c-expected
+++ b/tests/control-flow/local-clash-with-implicit-this.c-expected
@@ -1,6 +1,13 @@
 /* control_flow_local_clash_with_implicit_this.c generated by valac, the Vala compiler
  * generated from control_flow_local_clash_with_implicit_this.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/control-flow/lock-if-throw.c-expected b/tests/control-flow/lock-if-throw.c-expected
index 7eedf1239e55c12e..bd5502146eb4acc7 100644
--- a/tests/control-flow/lock-if-throw.c-expected
+++ b/tests/control-flow/lock-if-throw.c-expected
@@ -1,6 +1,13 @@
 /* control_flow_lock_if_throw.c generated by valac, the Vala compiler
  * generated from control_flow_lock_if_throw.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/control-flow/nested-conditional.c-expected b/tests/control-flow/nested-conditional.c-expected
index 75f1eba35a79172e..b013acf61392dd3f 100644
--- a/tests/control-flow/nested-conditional.c-expected
+++ b/tests/control-flow/nested-conditional.c-expected
@@ -1,6 +1,13 @@
 /* control_flow_nested_conditional.c generated by valac, the Vala compiler
  * generated from control_flow_nested_conditional.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/control-flow/null-conditional-bool.c-expected b/tests/control-flow/null-conditional-bool.c-expected
index 4ab15553a8a382c6..974ad3844cfa47b8 100644
--- a/tests/control-flow/null-conditional-bool.c-expected
+++ b/tests/control-flow/null-conditional-bool.c-expected
@@ -1,6 +1,13 @@
 /* control_flow_null_conditional_bool.c generated by valac, the Vala compiler
  * generated from control_flow_null_conditional_bool.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/control-flow/pre-post-increment-array-index.c-expected b/tests/control-flow/pre-post-increment-array-index.c-expected
index f10350740a66c31d..624b58e28e8e3959 100644
--- a/tests/control-flow/pre-post-increment-array-index.c-expected
+++ b/tests/control-flow/pre-post-increment-array-index.c-expected
@@ -1,6 +1,13 @@
 /* control_flow_pre_post_increment_array_index.c generated by valac, the Vala compiler
  * generated from control_flow_pre_post_increment_array_index.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #define _vala_assert(expr, msg) if G_LIKELY (expr) ; else g_assertion_message_expr (G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC, msg);
diff --git a/tests/control-flow/pre-post-increment-field.c-expected b/tests/control-flow/pre-post-increment-field.c-expected
index d8d16ceb56717989..c78f84cac7e8519a 100644
--- a/tests/control-flow/pre-post-increment-field.c-expected
+++ b/tests/control-flow/pre-post-increment-field.c-expected
@@ -1,6 +1,13 @@
 /* control_flow_pre_post_increment_field.c generated by valac, the Vala compiler
  * generated from control_flow_pre_post_increment_field.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/control-flow/pre-post-increment-local.c-expected b/tests/control-flow/pre-post-increment-local.c-expected
index fe58a03cb71ffce3..cec2c455627c4202 100644
--- a/tests/control-flow/pre-post-increment-local.c-expected
+++ b/tests/control-flow/pre-post-increment-local.c-expected
@@ -1,6 +1,13 @@
 /* control_flow_pre_post_increment_local.c generated by valac, the Vala compiler
  * generated from control_flow_pre_post_increment_local.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #define _vala_assert(expr, msg) if G_LIKELY (expr) ; else g_assertion_message_expr (G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC, msg);
diff --git a/tests/control-flow/pre-post-increment-parameter.c-expected b/tests/control-flow/pre-post-increment-parameter.c-expected
index 2e328efdc29b8aae..ac6ee3fcb6867cbe 100644
--- a/tests/control-flow/pre-post-increment-parameter.c-expected
+++ b/tests/control-flow/pre-post-increment-parameter.c-expected
@@ -1,6 +1,13 @@
 /* control_flow_pre_post_increment_parameter.c generated by valac, the Vala compiler
  * generated from control_flow_pre_post_increment_parameter.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/control-flow/pre-post-increment-property.c-expected b/tests/control-flow/pre-post-increment-property.c-expected
index 96949d2242a2300c..1e19b91454104dc9 100644
--- a/tests/control-flow/pre-post-increment-property.c-expected
+++ b/tests/control-flow/pre-post-increment-property.c-expected
@@ -1,6 +1,13 @@
 /* control_flow_pre_post_increment_property.c generated by valac, the Vala compiler
  * generated from control_flow_pre_post_increment_property.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/control-flow/pre-post-increment.c-expected b/tests/control-flow/pre-post-increment.c-expected
index 186e9f88fe5b27c8..4fbdb0908b02d7d1 100644
--- a/tests/control-flow/pre-post-increment.c-expected
+++ b/tests/control-flow/pre-post-increment.c-expected
@@ -1,6 +1,13 @@
 /* control_flow_pre_post_increment.c generated by valac, the Vala compiler
  * generated from control_flow_pre_post_increment.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #define _vala_assert(expr, msg) if G_LIKELY (expr) ; else g_assertion_message_expr (G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC, msg);
diff --git a/tests/control-flow/sideeffects.c-expected b/tests/control-flow/sideeffects.c-expected
index 81c928fd6bd6db8c..fca0a0ff94ea02f5 100644
--- a/tests/control-flow/sideeffects.c-expected
+++ b/tests/control-flow/sideeffects.c-expected
@@ -1,6 +1,13 @@
 /* control_flow_sideeffects.c generated by valac, the Vala compiler
  * generated from control_flow_sideeffects.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/control-flow/switch-enum.c-expected b/tests/control-flow/switch-enum.c-expected
index fc8507bc435ddeec..c547127d97923246 100644
--- a/tests/control-flow/switch-enum.c-expected
+++ b/tests/control-flow/switch-enum.c-expected
@@ -1,6 +1,13 @@
 /* control_flow_switch_enum.c generated by valac, the Vala compiler
  * generated from control_flow_switch_enum.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/control-flow/switch-string.c-expected b/tests/control-flow/switch-string.c-expected
index c8d66e6fff45bdfc..bec03a8efc833e49 100644
--- a/tests/control-flow/switch-string.c-expected
+++ b/tests/control-flow/switch-string.c-expected
@@ -1,6 +1,13 @@
 /* control_flow_switch_string.c generated by valac, the Vala compiler
  * generated from control_flow_switch_string.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/control-flow/switch.c-expected b/tests/control-flow/switch.c-expected
index 6e7834d96c77faeb..e546d781541b4fea 100644
--- a/tests/control-flow/switch.c-expected
+++ b/tests/control-flow/switch.c-expected
@@ -1,6 +1,13 @@
 /* control_flow_switch.c generated by valac, the Vala compiler
  * generated from control_flow_switch.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdio.h>
diff --git a/tests/control-flow/while-false.c-expected b/tests/control-flow/while-false.c-expected
index 63525993d6642cd3..00f357b1daf4dc2a 100644
--- a/tests/control-flow/while-false.c-expected
+++ b/tests/control-flow/while-false.c-expected
@@ -1,6 +1,13 @@
 /* control_flow_while_false.c generated by valac, the Vala compiler
  * generated from control_flow_while_false.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 static void _vala_main (void);
diff --git a/tests/dbus/arrays_client.c-expected b/tests/dbus/arrays_client.c-expected
index b46f5548d3812088..334815f84e5a2d79 100644
--- a/tests/dbus/arrays_client.c-expected
+++ b/tests/dbus/arrays_client.c-expected
@@ -1,6 +1,13 @@
 /* dbus_arrays_client.c generated by valac, the Vala compiler
  * generated from dbus_arrays_client.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/arrays_server.c-expected b/tests/dbus/arrays_server.c-expected
index e382242ddc6d3f9a..4e160ec4c0e3dd01 100644
--- a/tests/dbus/arrays_server.c-expected
+++ b/tests/dbus/arrays_server.c-expected
@@ -1,6 +1,13 @@
 /* dbus_arrays_server.c generated by valac, the Vala compiler
  * generated from dbus_arrays_server.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <stdlib.h>
diff --git a/tests/dbus/async-bus_client.c-expected b/tests/dbus/async-bus_client.c-expected
index dfac708c26aa1f3e..671afe0a3686a0f0 100644
--- a/tests/dbus/async-bus_client.c-expected
+++ b/tests/dbus/async-bus_client.c-expected
@@ -1,6 +1,13 @@
 /* dbus_async_bus_client.c generated by valac, the Vala compiler
  * generated from dbus_async_bus_client.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/async-bus_server.c-expected b/tests/dbus/async-bus_server.c-expected
index f26a333500a226eb..1221ccd58f4d28ea 100644
--- a/tests/dbus/async-bus_server.c-expected
+++ b/tests/dbus/async-bus_server.c-expected
@@ -1,6 +1,13 @@
 /* dbus_async_bus_server.c generated by valac, the Vala compiler
  * generated from dbus_async_bus_server.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/async-connection_client.c-expected b/tests/dbus/async-connection_client.c-expected
index c76d0834d484f19f..24646d981d2fcb56 100644
--- a/tests/dbus/async-connection_client.c-expected
+++ b/tests/dbus/async-connection_client.c-expected
@@ -1,6 +1,13 @@
 /* dbus_async_connection_client.c generated by valac, the Vala compiler
  * generated from dbus_async_connection_client.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/async-connection_server.c-expected b/tests/dbus/async-connection_server.c-expected
index ba068319983a7f80..0044a3e5f19239d7 100644
--- a/tests/dbus/async-connection_server.c-expected
+++ b/tests/dbus/async-connection_server.c-expected
@@ -1,6 +1,13 @@
 /* dbus_async_connection_server.c generated by valac, the Vala compiler
  * generated from dbus_async_connection_server.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/async-errors_client.c-expected b/tests/dbus/async-errors_client.c-expected
index 5733445517275ad3..e3822f6246033533 100644
--- a/tests/dbus/async-errors_client.c-expected
+++ b/tests/dbus/async-errors_client.c-expected
@@ -1,6 +1,13 @@
 /* dbus_async_errors_client.c generated by valac, the Vala compiler
  * generated from dbus_async_errors_client.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/async-errors_server.c-expected b/tests/dbus/async-errors_server.c-expected
index aaae816ebc227c3e..b9826d481b88dfef 100644
--- a/tests/dbus/async-errors_server.c-expected
+++ b/tests/dbus/async-errors_server.c-expected
@@ -1,6 +1,13 @@
 /* dbus_async_errors_server.c generated by valac, the Vala compiler
  * generated from dbus_async_errors_server.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/async-no-reply_client.c-expected b/tests/dbus/async-no-reply_client.c-expected
index 995bc1dc3da177ac..ba137230e6320d76 100644
--- a/tests/dbus/async-no-reply_client.c-expected
+++ b/tests/dbus/async-no-reply_client.c-expected
@@ -1,6 +1,13 @@
 /* dbus_async_no_reply_client.c generated by valac, the Vala compiler
  * generated from dbus_async_no_reply_client.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <stdlib.h>
diff --git a/tests/dbus/async-no-reply_server.c-expected b/tests/dbus/async-no-reply_server.c-expected
index e2e894c6054d5cba..8325b73a626f67b0 100644
--- a/tests/dbus/async-no-reply_server.c-expected
+++ b/tests/dbus/async-no-reply_server.c-expected
@@ -1,6 +1,13 @@
 /* dbus_async_no_reply_server.c generated by valac, the Vala compiler
  * generated from dbus_async_no_reply_server.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <stdlib.h>
diff --git a/tests/dbus/async_client.c-expected b/tests/dbus/async_client.c-expected
index c108a12b8bcd1628..7e606eada6ed7639 100644
--- a/tests/dbus/async_client.c-expected
+++ b/tests/dbus/async_client.c-expected
@@ -1,6 +1,13 @@
 /* dbus_async_client.c generated by valac, the Vala compiler
  * generated from dbus_async_client.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/async_server.c-expected b/tests/dbus/async_server.c-expected
index 81a1ee80b8f524c9..a8a20efaba841e78 100644
--- a/tests/dbus/async_server.c-expected
+++ b/tests/dbus/async_server.c-expected
@@ -1,6 +1,13 @@
 /* dbus_async_server.c generated by valac, the Vala compiler
  * generated from dbus_async_server.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/basic-types_client.c-expected b/tests/dbus/basic-types_client.c-expected
index 71da10ef26f023e7..cd2add7b71bed6b9 100644
--- a/tests/dbus/basic-types_client.c-expected
+++ b/tests/dbus/basic-types_client.c-expected
@@ -1,6 +1,13 @@
 /* dbus_basic_types_client.c generated by valac, the Vala compiler
  * generated from dbus_basic_types_client.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/basic-types_server.c-expected b/tests/dbus/basic-types_server.c-expected
index dd8f53d52e652118..af7c18375fe01382 100644
--- a/tests/dbus/basic-types_server.c-expected
+++ b/tests/dbus/basic-types_server.c-expected
@@ -1,6 +1,13 @@
 /* dbus_basic_types_server.c generated by valac, the Vala compiler
  * generated from dbus_basic_types_server.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <stdlib.h>
diff --git a/tests/dbus/bug596862.c-expected b/tests/dbus/bug596862.c-expected
index 0d0f8156914913e8..1c0bb8a9d64a7651 100644
--- a/tests/dbus/bug596862.c-expected
+++ b/tests/dbus/bug596862.c-expected
@@ -1,6 +1,13 @@
 /* dbus_bug596862.c generated by valac, the Vala compiler
  * generated from dbus_bug596862.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/bug602003_client.c-expected b/tests/dbus/bug602003_client.c-expected
index ec06c433ffe8df95..4070b6046304b95d 100644
--- a/tests/dbus/bug602003_client.c-expected
+++ b/tests/dbus/bug602003_client.c-expected
@@ -1,6 +1,13 @@
 /* dbus_bug602003_client.c generated by valac, the Vala compiler
  * generated from dbus_bug602003_client.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/bug602003_server.c-expected b/tests/dbus/bug602003_server.c-expected
index 7fe965ed631cef92..4a691a4b89ad82a1 100644
--- a/tests/dbus/bug602003_server.c-expected
+++ b/tests/dbus/bug602003_server.c-expected
@@ -1,6 +1,13 @@
 /* dbus_bug602003_server.c generated by valac, the Vala compiler
  * generated from dbus_bug602003_server.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/bug735437_client.c-expected b/tests/dbus/bug735437_client.c-expected
index dc44533a53ea92a9..639e708493e1c8d7 100644
--- a/tests/dbus/bug735437_client.c-expected
+++ b/tests/dbus/bug735437_client.c-expected
@@ -1,6 +1,13 @@
 /* dbus_bug735437_client.c generated by valac, the Vala compiler
  * generated from dbus_bug735437_client.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/bug735437_server.c-expected b/tests/dbus/bug735437_server.c-expected
index 82e199e41bf1f1f2..031bc352d458b15e 100644
--- a/tests/dbus/bug735437_server.c-expected
+++ b/tests/dbus/bug735437_server.c-expected
@@ -1,6 +1,13 @@
 /* dbus_bug735437_server.c generated by valac, the Vala compiler
  * generated from dbus_bug735437_server.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/bug782719_client.c-expected b/tests/dbus/bug782719_client.c-expected
index 22512e652c8040c1..e3beb1f65c60cfa6 100644
--- a/tests/dbus/bug782719_client.c-expected
+++ b/tests/dbus/bug782719_client.c-expected
@@ -1,6 +1,13 @@
 /* dbus_bug782719_client.c generated by valac, the Vala compiler
  * generated from dbus_bug782719_client.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/bug782719_server.c-expected b/tests/dbus/bug782719_server.c-expected
index 970ddcf5d9f3b473..79dd6bc18d453dc2 100644
--- a/tests/dbus/bug782719_server.c-expected
+++ b/tests/dbus/bug782719_server.c-expected
@@ -1,6 +1,13 @@
 /* dbus_bug782719_server.c generated by valac, the Vala compiler
  * generated from dbus_bug782719_server.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/bug783002_client.c-expected b/tests/dbus/bug783002_client.c-expected
index 270f433d4316622d..079de2d480b78b91 100644
--- a/tests/dbus/bug783002_client.c-expected
+++ b/tests/dbus/bug783002_client.c-expected
@@ -1,6 +1,13 @@
 /* dbus_bug783002_client.c generated by valac, the Vala compiler
  * generated from dbus_bug783002_client.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <stdlib.h>
diff --git a/tests/dbus/bug783002_server.c-expected b/tests/dbus/bug783002_server.c-expected
index 679154f0fa86737d..ef78c4a23c4692fa 100644
--- a/tests/dbus/bug783002_server.c-expected
+++ b/tests/dbus/bug783002_server.c-expected
@@ -1,6 +1,13 @@
 /* dbus_bug783002_server.c generated by valac, the Vala compiler
  * generated from dbus_bug783002_server.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <stdlib.h>
diff --git a/tests/dbus/bug792277.c-expected b/tests/dbus/bug792277.c-expected
index a9aca9d154500f17..a7be528e24644e16 100644
--- a/tests/dbus/bug792277.c-expected
+++ b/tests/dbus/bug792277.c-expected
@@ -1,6 +1,13 @@
 /* dbus_bug792277.c generated by valac, the Vala compiler
  * generated from dbus_bug792277.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/connection_client.c-expected b/tests/dbus/connection_client.c-expected
index ad172cced4f59a59..8bf298c61fc414f8 100644
--- a/tests/dbus/connection_client.c-expected
+++ b/tests/dbus/connection_client.c-expected
@@ -1,6 +1,13 @@
 /* dbus_connection_client.c generated by valac, the Vala compiler
  * generated from dbus_connection_client.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/connection_server.c-expected b/tests/dbus/connection_server.c-expected
index 561a66db63c3f4f0..f2f210f04ea793d9 100644
--- a/tests/dbus/connection_server.c-expected
+++ b/tests/dbus/connection_server.c-expected
@@ -1,6 +1,13 @@
 /* dbus_connection_server.c generated by valac, the Vala compiler
  * generated from dbus_connection_server.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/dicts_client.c-expected b/tests/dbus/dicts_client.c-expected
index ad7130d8fa2805f6..98cef6471d498574 100644
--- a/tests/dbus/dicts_client.c-expected
+++ b/tests/dbus/dicts_client.c-expected
@@ -1,6 +1,13 @@
 /* dbus_dicts_client.c generated by valac, the Vala compiler
  * generated from dbus_dicts_client.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/dicts_server.c-expected b/tests/dbus/dicts_server.c-expected
index 1e22e2c83d65aef0..7d2592291955ae2b 100644
--- a/tests/dbus/dicts_server.c-expected
+++ b/tests/dbus/dicts_server.c-expected
@@ -1,6 +1,13 @@
 /* dbus_dicts_server.c generated by valac, the Vala compiler
  * generated from dbus_dicts_server.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/dynamic-method_client.c-expected b/tests/dbus/dynamic-method_client.c-expected
index d06bec69df7cbdbf..ea6439e8154c4bd2 100644
--- a/tests/dbus/dynamic-method_client.c-expected
+++ b/tests/dbus/dynamic-method_client.c-expected
@@ -1,6 +1,13 @@
 /* dbus_dynamic_method_client.c generated by valac, the Vala compiler
  * generated from dbus_dynamic_method_client.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <gio/gio.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/dbus/dynamic-method_server.c-expected b/tests/dbus/dynamic-method_server.c-expected
index 926a5b25d4253b90..e26711b2732559be 100644
--- a/tests/dbus/dynamic-method_server.c-expected
+++ b/tests/dbus/dynamic-method_server.c-expected
@@ -1,6 +1,13 @@
 /* dbus_dynamic_method_server.c generated by valac, the Vala compiler
  * generated from dbus_dynamic_method_server.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/enum-string-marshalling.c-expected b/tests/dbus/enum-string-marshalling.c-expected
index 2694775d2e605413..ca71e1b0aed3c6dc 100644
--- a/tests/dbus/enum-string-marshalling.c-expected
+++ b/tests/dbus/enum-string-marshalling.c-expected
@@ -1,6 +1,13 @@
 /* dbus_enum_string_marshalling.c generated by valac, the Vala compiler
  * generated from dbus_enum_string_marshalling.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <string.h>
 #include <gio/gio.h>
diff --git a/tests/dbus/errors_client.c-expected b/tests/dbus/errors_client.c-expected
index a7c9fdd65391167c..b5522bcfa1cfdd3a 100644
--- a/tests/dbus/errors_client.c-expected
+++ b/tests/dbus/errors_client.c-expected
@@ -1,6 +1,13 @@
 /* dbus_errors_client.c generated by valac, the Vala compiler
  * generated from dbus_errors_client.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <gio/gio.h>
 #include <glib.h>
 #include <glib-object.h>
diff --git a/tests/dbus/errors_server.c-expected b/tests/dbus/errors_server.c-expected
index 26e66c8e1610170b..4bc4365417835017 100644
--- a/tests/dbus/errors_server.c-expected
+++ b/tests/dbus/errors_server.c-expected
@@ -1,6 +1,13 @@
 /* dbus_errors_server.c generated by valac, the Vala compiler
  * generated from dbus_errors_server.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <gio/gio.h>
 #include <glib.h>
 #include <glib-object.h>
diff --git a/tests/dbus/filedescriptor-async_client.c-expected b/tests/dbus/filedescriptor-async_client.c-expected
index b458ecf0236eff1f..64bcd3e9e06ef93e 100644
--- a/tests/dbus/filedescriptor-async_client.c-expected
+++ b/tests/dbus/filedescriptor-async_client.c-expected
@@ -1,6 +1,13 @@
 /* dbus_filedescriptor_async_client.c generated by valac, the Vala compiler
  * generated from dbus_filedescriptor_async_client.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <gio/gunixinputstream.h>
diff --git a/tests/dbus/filedescriptor-async_server.c-expected b/tests/dbus/filedescriptor-async_server.c-expected
index 5c9aa9720580f798..f2be68aabd5069db 100644
--- a/tests/dbus/filedescriptor-async_server.c-expected
+++ b/tests/dbus/filedescriptor-async_server.c-expected
@@ -1,6 +1,13 @@
 /* dbus_filedescriptor_async_server.c generated by valac, the Vala compiler
  * generated from dbus_filedescriptor_async_server.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <gio/gunixinputstream.h>
diff --git a/tests/dbus/filedescriptor-errors_client.c-expected b/tests/dbus/filedescriptor-errors_client.c-expected
index 13e5b50bcc33731a..7154b75373dd16d8 100644
--- a/tests/dbus/filedescriptor-errors_client.c-expected
+++ b/tests/dbus/filedescriptor-errors_client.c-expected
@@ -1,6 +1,13 @@
 /* dbus_filedescriptor_errors_client.c generated by valac, the Vala compiler
  * generated from dbus_filedescriptor_errors_client.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <gio/gunixoutputstream.h>
diff --git a/tests/dbus/filedescriptor-errors_server.c-expected b/tests/dbus/filedescriptor-errors_server.c-expected
index 23c14621b96289fc..72556fe698dbcc07 100644
--- a/tests/dbus/filedescriptor-errors_server.c-expected
+++ b/tests/dbus/filedescriptor-errors_server.c-expected
@@ -1,6 +1,13 @@
 /* dbus_filedescriptor_errors_server.c generated by valac, the Vala compiler
  * generated from dbus_filedescriptor_errors_server.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <gio/gunixoutputstream.h>
diff --git a/tests/dbus/filedescriptor_client.c-expected b/tests/dbus/filedescriptor_client.c-expected
index 1a3a8473af911e4f..07e2d4de3d6631ca 100644
--- a/tests/dbus/filedescriptor_client.c-expected
+++ b/tests/dbus/filedescriptor_client.c-expected
@@ -1,6 +1,13 @@
 /* dbus_filedescriptor_client.c generated by valac, the Vala compiler
  * generated from dbus_filedescriptor_client.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <gio/gunixinputstream.h>
diff --git a/tests/dbus/filedescriptor_server.c-expected b/tests/dbus/filedescriptor_server.c-expected
index 4ff455497db9f800..80d4b7d58b9526b7 100644
--- a/tests/dbus/filedescriptor_server.c-expected
+++ b/tests/dbus/filedescriptor_server.c-expected
@@ -1,6 +1,13 @@
 /* dbus_filedescriptor_server.c generated by valac, the Vala compiler
  * generated from dbus_filedescriptor_server.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <gio/gunixinputstream.h>
diff --git a/tests/dbus/generics_client.c-expected b/tests/dbus/generics_client.c-expected
index 358753685b1a7dab..a5172dbdf7a52782 100644
--- a/tests/dbus/generics_client.c-expected
+++ b/tests/dbus/generics_client.c-expected
@@ -1,6 +1,13 @@
 /* dbus_generics_client.c generated by valac, the Vala compiler
  * generated from dbus_generics_client.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/generics_server.c-expected b/tests/dbus/generics_server.c-expected
index e7b173f862445d09..a8d2d2573c703e73 100644
--- a/tests/dbus/generics_server.c-expected
+++ b/tests/dbus/generics_server.c-expected
@@ -1,6 +1,13 @@
 /* dbus_generics_server.c generated by valac, the Vala compiler
  * generated from dbus_generics_server.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/interface-info_client.c-expected b/tests/dbus/interface-info_client.c-expected
index 3822e2dc3db23a52..9513b418f781be46 100644
--- a/tests/dbus/interface-info_client.c-expected
+++ b/tests/dbus/interface-info_client.c-expected
@@ -1,6 +1,13 @@
 /* dbus_interface_info_client.c generated by valac, the Vala compiler
  * generated from dbus_interface_info_client.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <stdlib.h>
diff --git a/tests/dbus/interface-info_server.c-expected b/tests/dbus/interface-info_server.c-expected
index a23553fda0a8b212..6b9eba8e727babe5 100644
--- a/tests/dbus/interface-info_server.c-expected
+++ b/tests/dbus/interface-info_server.c-expected
@@ -1,6 +1,13 @@
 /* dbus_interface_info_server.c generated by valac, the Vala compiler
  * generated from dbus_interface_info_server.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/no-reply_client.c-expected b/tests/dbus/no-reply_client.c-expected
index 354f61cbb5a4abfd..205f2d74ce7ea1fa 100644
--- a/tests/dbus/no-reply_client.c-expected
+++ b/tests/dbus/no-reply_client.c-expected
@@ -1,6 +1,13 @@
 /* dbus_no_reply_client.c generated by valac, the Vala compiler
  * generated from dbus_no_reply_client.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <stdlib.h>
diff --git a/tests/dbus/no-reply_server.c-expected b/tests/dbus/no-reply_server.c-expected
index c1f2584a7ac08fad..3cf72c8bcecb5cf8 100644
--- a/tests/dbus/no-reply_server.c-expected
+++ b/tests/dbus/no-reply_server.c-expected
@@ -1,6 +1,13 @@
 /* dbus_no_reply_server.c generated by valac, the Vala compiler
  * generated from dbus_no_reply_server.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <stdlib.h>
diff --git a/tests/dbus/rawvariants_client.c-expected b/tests/dbus/rawvariants_client.c-expected
index 801109028e7ff8c9..86f82b7591051f1b 100644
--- a/tests/dbus/rawvariants_client.c-expected
+++ b/tests/dbus/rawvariants_client.c-expected
@@ -1,6 +1,13 @@
 /* dbus_rawvariants_client.c generated by valac, the Vala compiler
  * generated from dbus_rawvariants_client.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/rawvariants_server.c-expected b/tests/dbus/rawvariants_server.c-expected
index ec24125dec74f462..37c9bdc2c99e2289 100644
--- a/tests/dbus/rawvariants_server.c-expected
+++ b/tests/dbus/rawvariants_server.c-expected
@@ -1,6 +1,13 @@
 /* dbus_rawvariants_server.c generated by valac, the Vala compiler
  * generated from dbus_rawvariants_server.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <stdlib.h>
diff --git a/tests/dbus/signals_client.c-expected b/tests/dbus/signals_client.c-expected
index 9442943e9f199bc6..c579692cb5a1346d 100644
--- a/tests/dbus/signals_client.c-expected
+++ b/tests/dbus/signals_client.c-expected
@@ -1,6 +1,13 @@
 /* dbus_signals_client.c generated by valac, the Vala compiler
  * generated from dbus_signals_client.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/signals_server.c-expected b/tests/dbus/signals_server.c-expected
index 9f9c78102a118dfb..aa87b8933afc4b66 100644
--- a/tests/dbus/signals_server.c-expected
+++ b/tests/dbus/signals_server.c-expected
@@ -1,6 +1,13 @@
 /* dbus_signals_server.c generated by valac, the Vala compiler
  * generated from dbus_signals_server.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/structs_client.c-expected b/tests/dbus/structs_client.c-expected
index 00223fea23f074cb..792dc62eb5ede8f8 100644
--- a/tests/dbus/structs_client.c-expected
+++ b/tests/dbus/structs_client.c-expected
@@ -1,6 +1,13 @@
 /* dbus_structs_client.c generated by valac, the Vala compiler
  * generated from dbus_structs_client.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/dbus/structs_server.c-expected b/tests/dbus/structs_server.c-expected
index 83250e523481f0dd..440236e0d8c4d00a 100644
--- a/tests/dbus/structs_server.c-expected
+++ b/tests/dbus/structs_server.c-expected
@@ -1,6 +1,13 @@
 /* dbus_structs_server.c generated by valac, the Vala compiler
  * generated from dbus_structs_server.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/delegates/bug539166.c-expected b/tests/delegates/bug539166.c-expected
index c335a36fe367d0f3..f63dda756cc037fe 100644
--- a/tests/delegates/bug539166.c-expected
+++ b/tests/delegates/bug539166.c-expected
@@ -1,6 +1,13 @@
 /* delegates_bug539166.c generated by valac, the Vala compiler
  * generated from delegates_bug539166.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/delegates/bug595610.c-expected b/tests/delegates/bug595610.c-expected
index 898b76b6554f8da3..a1eaac2a85b6d6df 100644
--- a/tests/delegates/bug595610.c-expected
+++ b/tests/delegates/bug595610.c-expected
@@ -1,6 +1,13 @@
 /* delegates_bug595610.c generated by valac, the Vala compiler
  * generated from delegates_bug595610.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/delegates/bug595639.c-expected b/tests/delegates/bug595639.c-expected
index c39528bf71099ad8..61c4b822413a1b57 100644
--- a/tests/delegates/bug595639.c-expected
+++ b/tests/delegates/bug595639.c-expected
@@ -1,6 +1,13 @@
 /* delegates_bug595639.c generated by valac, the Vala compiler
  * generated from delegates_bug595639.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/delegates/bug638415.c-expected b/tests/delegates/bug638415.c-expected
index 367a2cc95866c1a1..e353bc3de6d9c801 100644
--- a/tests/delegates/bug638415.c-expected
+++ b/tests/delegates/bug638415.c-expected
@@ -1,6 +1,13 @@
 /* delegates_bug638415.c generated by valac, the Vala compiler
  * generated from delegates_bug638415.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/delegates/bug639751.c-expected b/tests/delegates/bug639751.c-expected
index b0586a6fd8b692da..ddb3c5fa2cc77b5b 100644
--- a/tests/delegates/bug639751.c-expected
+++ b/tests/delegates/bug639751.c-expected
@@ -1,6 +1,13 @@
 /* delegates_bug639751.c generated by valac, the Vala compiler
  * generated from delegates_bug639751.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/delegates/bug659778.c-expected b/tests/delegates/bug659778.c-expected
index 135d5f436788990a..4d453049a2c73450 100644
--- a/tests/delegates/bug659778.c-expected
+++ b/tests/delegates/bug659778.c-expected
@@ -1,6 +1,13 @@
 /* delegates_bug659778.c generated by valac, the Vala compiler
  * generated from delegates_bug659778.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/delegates/bug683925.c-expected b/tests/delegates/bug683925.c-expected
index cc747164a02b82ce..b994f294484cd7f3 100644
--- a/tests/delegates/bug683925.c-expected
+++ b/tests/delegates/bug683925.c-expected
@@ -1,6 +1,13 @@
 /* delegates_bug683925.c generated by valac, the Vala compiler
  * generated from delegates_bug683925.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/delegates/bug703804.c-expected b/tests/delegates/bug703804.c-expected
index b26578a3b75a54c3..24b684b9002949ac 100644
--- a/tests/delegates/bug703804.c-expected
+++ b/tests/delegates/bug703804.c-expected
@@ -1,6 +1,13 @@
 /* delegates_bug703804.c generated by valac, the Vala compiler
  * generated from delegates_bug703804.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/delegates/bug761360.c-expected b/tests/delegates/bug761360.c-expected
index f180a86d7dc31ad8..1b7e78a1da5f3b8d 100644
--- a/tests/delegates/bug761360.c-expected
+++ b/tests/delegates/bug761360.c-expected
@@ -1,6 +1,13 @@
 /* delegates_bug761360.c generated by valac, the Vala compiler
  * generated from delegates_bug761360.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 typedef gint* (*ArrayReturnFunc) (gint* result_length1, gpointer user_data);
diff --git a/tests/delegates/bug792077.c-expected b/tests/delegates/bug792077.c-expected
index 5abd863a4855d215..e64d16c62895081c 100644
--- a/tests/delegates/bug792077.c-expected
+++ b/tests/delegates/bug792077.c-expected
@@ -1,6 +1,13 @@
 /* delegates_bug792077.c generated by valac, the Vala compiler
  * generated from delegates_bug792077.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/delegates/casting.c-expected b/tests/delegates/casting.c-expected
index fe15b7acfe2323a6..5d89270827c63dce 100644
--- a/tests/delegates/casting.c-expected
+++ b/tests/delegates/casting.c-expected
@@ -1,6 +1,13 @@
 /* delegates_casting.c generated by valac, the Vala compiler
  * generated from delegates_casting.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/delegates/class-field-initializer.c-expected b/tests/delegates/class-field-initializer.c-expected
index c2113884885af971..64de93067038f226 100644
--- a/tests/delegates/class-field-initializer.c-expected
+++ b/tests/delegates/class-field-initializer.c-expected
@@ -1,6 +1,13 @@
 /* delegates_class_field_initializer.c generated by valac, the Vala compiler
  * generated from delegates_class_field_initializer.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/delegates/compatible.c-expected b/tests/delegates/compatible.c-expected
index 3eaecad79c84c616..d23cbe59186cf571 100644
--- a/tests/delegates/compatible.c-expected
+++ b/tests/delegates/compatible.c-expected
@@ -1,6 +1,13 @@
 /* delegates_compatible.c generated by valac, the Vala compiler
  * generated from delegates_compatible.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/delegates/delegate-recusive.c-expected b/tests/delegates/delegate-recusive.c-expected
index fcafb34a5dab1898..8608d9a687c4d44e 100644
--- a/tests/delegates/delegate-recusive.c-expected
+++ b/tests/delegates/delegate-recusive.c-expected
@@ -1,6 +1,13 @@
 /* delegates_delegate_recusive.c generated by valac, the Vala compiler
  * generated from delegates_delegate_recusive.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/delegates/delegate_only.c-expected b/tests/delegates/delegate_only.c-expected
index dfcf7a5d2df10fa0..78669152ff100258 100644
--- a/tests/delegates/delegate_only.c-expected
+++ b/tests/delegates/delegate_only.c-expected
@@ -1,6 +1,13 @@
 /* delegates_delegate_only.c generated by valac, the Vala compiler
  * generated from delegates_delegate_only.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 typedef void (*FooFunc) (gpointer user_data);
diff --git a/tests/delegates/delegates.c-expected b/tests/delegates/delegates.c-expected
index 06d31b398b22f6b2..4a69f58122ae76ed 100644
--- a/tests/delegates/delegates.c-expected
+++ b/tests/delegates/delegates.c-expected
@@ -1,6 +1,13 @@
 /* delegates_delegates.c generated by valac, the Vala compiler
  * generated from delegates_delegates.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/delegates/error-pos.c-expected b/tests/delegates/error-pos.c-expected
index 9a4a338f754ae637..29339114343929b7 100644
--- a/tests/delegates/error-pos.c-expected
+++ b/tests/delegates/error-pos.c-expected
@@ -1,6 +1,13 @@
 /* delegates_error_pos.c generated by valac, the Vala compiler
  * generated from delegates_error_pos.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <stdlib.h>
diff --git a/tests/delegates/fields-no-target.c-expected b/tests/delegates/fields-no-target.c-expected
index d065ea232c78868c..ee1eec3251b64c45 100644
--- a/tests/delegates/fields-no-target.c-expected
+++ b/tests/delegates/fields-no-target.c-expected
@@ -1,6 +1,13 @@
 /* delegates_fields_no_target.c generated by valac, the Vala compiler
  * generated from delegates_fields_no_target.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <string.h>
diff --git a/tests/delegates/fields.c-expected b/tests/delegates/fields.c-expected
index 3b4ae26fc8bb8ccd..f050dd5cded11f7c 100644
--- a/tests/delegates/fields.c-expected
+++ b/tests/delegates/fields.c-expected
@@ -1,6 +1,13 @@
 /* delegates_fields.c generated by valac, the Vala compiler
  * generated from delegates_fields.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/delegates/gclosure-conversion.c-expected b/tests/delegates/gclosure-conversion.c-expected
index 916299d7c6d64772..1b9321e6ace6c5bc 100644
--- a/tests/delegates/gclosure-conversion.c-expected
+++ b/tests/delegates/gclosure-conversion.c-expected
@@ -1,6 +1,13 @@
 /* delegates_gclosure_conversion.c generated by valac, the Vala compiler
  * generated from delegates_gclosure_conversion.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/delegates/implicit-local-variable.c-expected b/tests/delegates/implicit-local-variable.c-expected
index 48922109698f1f3f..b3b000a49880f1ab 100644
--- a/tests/delegates/implicit-local-variable.c-expected
+++ b/tests/delegates/implicit-local-variable.c-expected
@@ -1,6 +1,13 @@
 /* delegates_implicit_local_variable.c generated by valac, the Vala compiler
  * generated from delegates_implicit_local_variable.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 typedef gboolean (*GSourceDispatchFunc) (GSource* source, GSourceFunc _callback, gpointer _callback_target);
diff --git a/tests/delegates/lambda-mixed-instance-static.c-expected b/tests/delegates/lambda-mixed-instance-static.c-expected
index 1beb45a964aeef21..0d10b3cb7b159e82 100644
--- a/tests/delegates/lambda-mixed-instance-static.c-expected
+++ b/tests/delegates/lambda-mixed-instance-static.c-expected
@@ -1,6 +1,13 @@
 /* delegates_lambda_mixed_instance_static.c generated by valac, the Vala compiler
  * generated from delegates_lambda_mixed_instance_static.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/delegates/lambda-shared-closure.c-expected b/tests/delegates/lambda-shared-closure.c-expected
index 7d99502c3d6bebbf..98dbaa60b9fe7b1a 100644
--- a/tests/delegates/lambda-shared-closure.c-expected
+++ b/tests/delegates/lambda-shared-closure.c-expected
@@ -1,6 +1,13 @@
 /* delegates_lambda_shared_closure.c generated by valac, the Vala compiler
  * generated from delegates_lambda_shared_closure.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/delegates/member-target-destroy-2.c-expected b/tests/delegates/member-target-destroy-2.c-expected
index 17b11e2237fd0247..9508148998e59b37 100644
--- a/tests/delegates/member-target-destroy-2.c-expected
+++ b/tests/delegates/member-target-destroy-2.c-expected
@@ -1,6 +1,13 @@
 /* delegates_member_target_destroy_2.c generated by valac, the Vala compiler
  * generated from delegates_member_target_destroy_2.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/delegates/member-target-destroy.c-expected b/tests/delegates/member-target-destroy.c-expected
index 0fd0ff7146d6eb56..2ae35eea06946189 100644
--- a/tests/delegates/member-target-destroy.c-expected
+++ b/tests/delegates/member-target-destroy.c-expected
@@ -1,6 +1,13 @@
 /* delegates_member_target_destroy.c generated by valac, the Vala compiler
  * generated from delegates_member_target_destroy.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/delegates/params-array-with-throws.c-expected b/tests/delegates/params-array-with-throws.c-expected
index 024eed82b7d03c78..d83948f2c4b0da01 100644
--- a/tests/delegates/params-array-with-throws.c-expected
+++ b/tests/delegates/params-array-with-throws.c-expected
@@ -1,6 +1,13 @@
 /* delegates_params_array_with_throws.c generated by valac, the Vala compiler
  * generated from delegates_params_array_with_throws.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <stdlib.h>
diff --git a/tests/delegates/params-array.c-expected b/tests/delegates/params-array.c-expected
index 701827b18ef5bd44..bf0fc6a0a76a4a3b 100644
--- a/tests/delegates/params-array.c-expected
+++ b/tests/delegates/params-array.c-expected
@@ -1,6 +1,13 @@
 /* delegates_params_array.c generated by valac, the Vala compiler
  * generated from delegates_params_array.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/delegates/reference_transfer.c-expected b/tests/delegates/reference_transfer.c-expected
index 9a8d00e42de53097..9bdb9bdf5a48f300 100644
--- a/tests/delegates/reference_transfer.c-expected
+++ b/tests/delegates/reference_transfer.c-expected
@@ -1,6 +1,13 @@
 /* delegates_reference_transfer.c generated by valac, the Vala compiler
  * generated from delegates_reference_transfer.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/delegates/return-array-null-terminated.c-expected b/tests/delegates/return-array-null-terminated.c-expected
index 4a89bb8f973914d7..d295a4ffb6ae13b2 100644
--- a/tests/delegates/return-array-null-terminated.c-expected
+++ b/tests/delegates/return-array-null-terminated.c-expected
@@ -1,6 +1,13 @@
 /* delegates_return_array_null_terminated.c generated by valac, the Vala compiler
  * generated from delegates_return_array_null_terminated.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/delegates/variadic.c-expected b/tests/delegates/variadic.c-expected
index e390cc4567cc8c98..6d122ca60a39c305 100644
--- a/tests/delegates/variadic.c-expected
+++ b/tests/delegates/variadic.c-expected
@@ -1,6 +1,13 @@
 /* delegates_variadic.c generated by valac, the Vala compiler
  * generated from delegates_variadic.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/delegates/wrapper.c-expected b/tests/delegates/wrapper.c-expected
index 361445eccbd10e99..739f1503c1ce1e95 100644
--- a/tests/delegates/wrapper.c-expected
+++ b/tests/delegates/wrapper.c-expected
@@ -1,6 +1,13 @@
 /* delegates_wrapper.c generated by valac, the Vala compiler
  * generated from delegates_wrapper.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/enums/bug614424.c-expected b/tests/enums/bug614424.c-expected
index 70268aa83cae8768..692b54c177dfb1f2 100644
--- a/tests/enums/bug614424.c-expected
+++ b/tests/enums/bug614424.c-expected
@@ -1,6 +1,13 @@
 /* enums_bug614424.c generated by valac, the Vala compiler
  * generated from enums_bug614424.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/enums/bug666035.c-expected b/tests/enums/bug666035.c-expected
index cbc78c93b3634896..4f8a292e496a1ddc 100644
--- a/tests/enums/bug666035.c-expected
+++ b/tests/enums/bug666035.c-expected
@@ -1,6 +1,13 @@
 /* enums_bug666035.c generated by valac, the Vala compiler
  * generated from enums_bug666035.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/enums/bug673879.c-expected b/tests/enums/bug673879.c-expected
index 98853ff129eb8d04..93d80c1856e9b5af 100644
--- a/tests/enums/bug673879.c-expected
+++ b/tests/enums/bug673879.c-expected
@@ -1,6 +1,13 @@
 /* enums_bug673879.c generated by valac, the Vala compiler
  * generated from enums_bug673879.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/enums/bug763831.c-expected b/tests/enums/bug763831.c-expected
index 94bdf4ed5f7676a2..26297493a88ae4fd 100644
--- a/tests/enums/bug763831.c-expected
+++ b/tests/enums/bug763831.c-expected
@@ -1,6 +1,13 @@
 /* enums_bug763831.c generated by valac, the Vala compiler
  * generated from enums_bug763831.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/enums/bug780050.c-expected b/tests/enums/bug780050.c-expected
index a9f1f51e61cca1e1..401384e5a68edbfa 100644
--- a/tests/enums/bug780050.c-expected
+++ b/tests/enums/bug780050.c-expected
@@ -1,6 +1,13 @@
 /* enums_bug780050.c generated by valac, the Vala compiler
  * generated from enums_bug780050.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/enums/default-gtype.c-expected b/tests/enums/default-gtype.c-expected
index 41b4b2970913c337..247cf6e55ba1c5c0 100644
--- a/tests/enums/default-gtype.c-expected
+++ b/tests/enums/default-gtype.c-expected
@@ -1,6 +1,13 @@
 /* enums_default_gtype.c generated by valac, the Vala compiler
  * generated from enums_default_gtype.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/enums/enum-boxed.c-expected b/tests/enums/enum-boxed.c-expected
index 56ed9339ce382205..b18192982e55245b 100644
--- a/tests/enums/enum-boxed.c-expected
+++ b/tests/enums/enum-boxed.c-expected
@@ -1,6 +1,13 @@
 /* enums_enum_boxed.c generated by valac, the Vala compiler
  * generated from enums_enum_boxed.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/enums/enum-no-gtype.c-expected b/tests/enums/enum-no-gtype.c-expected
index c2a05e86dc3fe5ab..c664a74f3ff6a1a7 100644
--- a/tests/enums/enum-no-gtype.c-expected
+++ b/tests/enums/enum-no-gtype.c-expected
@@ -1,6 +1,13 @@
 /* enums_enum_no_gtype.c generated by valac, the Vala compiler
  * generated from enums_enum_no_gtype.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 typedef enum  {
 	FOO_BAR,
 	FOO_BAZ
diff --git a/tests/enums/enum_only.c-expected b/tests/enums/enum_only.c-expected
index 9162eace41e48f56..7e3795d10fe8e3c9 100644
--- a/tests/enums/enum_only.c-expected
+++ b/tests/enums/enum_only.c-expected
@@ -1,6 +1,13 @@
 /* enums_enum_only.c generated by valac, the Vala compiler
  * generated from enums_enum_only.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/enums/enums.c-expected b/tests/enums/enums.c-expected
index a6594015bb5723ed..b49a27a2ef9a24b4 100644
--- a/tests/enums/enums.c-expected
+++ b/tests/enums/enums.c-expected
@@ -1,6 +1,13 @@
 /* enums_enums.c generated by valac, the Vala compiler
  * generated from enums_enums.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdio.h>
diff --git a/tests/enums/flags.c-expected b/tests/enums/flags.c-expected
index d44b84f8989d0c7e..b83da037fca43b12 100644
--- a/tests/enums/flags.c-expected
+++ b/tests/enums/flags.c-expected
@@ -1,6 +1,13 @@
 /* enums_flags.c generated by valac, the Vala compiler
  * generated from enums_flags.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/enums/from-0-literal.c-expected b/tests/enums/from-0-literal.c-expected
index e06f40799839cf7c..af4acd62d95a938c 100644
--- a/tests/enums/from-0-literal.c-expected
+++ b/tests/enums/from-0-literal.c-expected
@@ -1,6 +1,13 @@
 /* enums_from_0_literal.c generated by valac, the Vala compiler
  * generated from enums_from_0_literal.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/enums/in-inference.c-expected b/tests/enums/in-inference.c-expected
index c859a06765afde86..4e99ad0adc9340d7 100644
--- a/tests/enums/in-inference.c-expected
+++ b/tests/enums/in-inference.c-expected
@@ -1,6 +1,13 @@
 /* enums_in_inference.c generated by valac, the Vala compiler
  * generated from enums_in_inference.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/enums/no_gtype_to_string.c-expected b/tests/enums/no_gtype_to_string.c-expected
index 89201fa8b705cb48..624b91afd146b496 100644
--- a/tests/enums/no_gtype_to_string.c-expected
+++ b/tests/enums/no_gtype_to_string.c-expected
@@ -1,6 +1,13 @@
 /* enums_no_gtype_to_string.c generated by valac, the Vala compiler
  * generated from enums_no_gtype_to_string.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <stdlib.h>
diff --git a/tests/enums/switch.c-expected b/tests/enums/switch.c-expected
index 91c674d3b4530112..cb032dcec427fdd2 100644
--- a/tests/enums/switch.c-expected
+++ b/tests/enums/switch.c-expected
@@ -1,6 +1,13 @@
 /* enums_switch.c generated by valac, the Vala compiler
  * generated from enums_switch.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/enums/unsafe-assignment.c-expected b/tests/enums/unsafe-assignment.c-expected
index ba8ac7084bb1fc47..a0cf9ac87bb78188 100644
--- a/tests/enums/unsafe-assignment.c-expected
+++ b/tests/enums/unsafe-assignment.c-expected
@@ -1,6 +1,13 @@
 /* enums_unsafe_assignment.c generated by valac, the Vala compiler
  * generated from enums_unsafe_assignment.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/errors/bug567181.c-expected b/tests/errors/bug567181.c-expected
index b2af28b59344a39a..22eeb8f0be73e8b3 100644
--- a/tests/errors/bug567181.c-expected
+++ b/tests/errors/bug567181.c-expected
@@ -1,6 +1,13 @@
 /* errors_bug567181.c generated by valac, the Vala compiler
  * generated from errors_bug567181.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/errors/bug579101.c-expected b/tests/errors/bug579101.c-expected
index ea1a7f7773ee35ff..dd4ed0bed3d144a2 100644
--- a/tests/errors/bug579101.c-expected
+++ b/tests/errors/bug579101.c-expected
@@ -1,6 +1,13 @@
 /* errors_bug579101.c generated by valac, the Vala compiler
  * generated from errors_bug579101.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <stdlib.h>
diff --git a/tests/errors/bug596228.c-expected b/tests/errors/bug596228.c-expected
index 11172b49d9fb4532..5c6367feeb83788b 100644
--- a/tests/errors/bug596228.c-expected
+++ b/tests/errors/bug596228.c-expected
@@ -1,6 +1,13 @@
 /* errors_bug596228.c generated by valac, the Vala compiler
  * generated from errors_bug596228.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/errors/bug623049.c-expected b/tests/errors/bug623049.c-expected
index f7a79c44ae780dce..66fc7c13f851165b 100644
--- a/tests/errors/bug623049.c-expected
+++ b/tests/errors/bug623049.c-expected
@@ -1,6 +1,13 @@
 /* errors_bug623049.c generated by valac, the Vala compiler
  * generated from errors_bug623049.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/errors/bug627090.c-expected b/tests/errors/bug627090.c-expected
index 6ad044d7ecb2848b..4cceac3c8b5c9e8a 100644
--- a/tests/errors/bug627090.c-expected
+++ b/tests/errors/bug627090.c-expected
@@ -1,6 +1,13 @@
 /* errors_bug627090.c generated by valac, the Vala compiler
  * generated from errors_bug627090.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/errors/bug639589.c-expected b/tests/errors/bug639589.c-expected
index f3e3c8212971f222..f21af5c552d95905 100644
--- a/tests/errors/bug639589.c-expected
+++ b/tests/errors/bug639589.c-expected
@@ -1,6 +1,13 @@
 /* errors_bug639589.c generated by valac, the Vala compiler
  * generated from errors_bug639589.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <stdlib.h>
diff --git a/tests/errors/bug651145.c-expected b/tests/errors/bug651145.c-expected
index 484bf6432d247dbb..48fbcfd2e0a47cc1 100644
--- a/tests/errors/bug651145.c-expected
+++ b/tests/errors/bug651145.c-expected
@@ -1,6 +1,13 @@
 /* errors_bug651145.c generated by valac, the Vala compiler
  * generated from errors_bug651145.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/errors/bug762377.c-expected b/tests/errors/bug762377.c-expected
index dfb878ef77879476..2bff7fd21bb7c84a 100644
--- a/tests/errors/bug762377.c-expected
+++ b/tests/errors/bug762377.c-expected
@@ -1,6 +1,13 @@
 /* errors_bug762377.c generated by valac, the Vala compiler
  * generated from errors_bug762377.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <gio/gio.h>
 #include <glib-object.h>
 #include <glib.h>
diff --git a/tests/errors/bug778224.c-expected b/tests/errors/bug778224.c-expected
index 8f0e3c06d3134e24..2a511548929293b4 100644
--- a/tests/errors/bug778224.c-expected
+++ b/tests/errors/bug778224.c-expected
@@ -1,6 +1,13 @@
 /* errors_bug778224.c generated by valac, the Vala compiler
  * generated from errors_bug778224.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/errors/catch-error-code.c-expected b/tests/errors/catch-error-code.c-expected
index 7e8c9a55f5e6d027..d835e27bae63a92c 100644
--- a/tests/errors/catch-error-code.c-expected
+++ b/tests/errors/catch-error-code.c-expected
@@ -1,6 +1,13 @@
 /* errors_catch_error_code.c generated by valac, the Vala compiler
  * generated from errors_catch_error_code.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/errors/catch-in-finally.c-expected b/tests/errors/catch-in-finally.c-expected
index 299b83db10c9dc4e..35fb98d9c0dc24ba 100644
--- a/tests/errors/catch-in-finally.c-expected
+++ b/tests/errors/catch-in-finally.c-expected
@@ -1,6 +1,13 @@
 /* errors_catch_in_finally.c generated by valac, the Vala compiler
  * generated from errors_catch_in_finally.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <stdlib.h>
diff --git a/tests/errors/default-gtype.c-expected b/tests/errors/default-gtype.c-expected
index eba50fda8633b707..4f3ca5031be4dc93 100644
--- a/tests/errors/default-gtype.c-expected
+++ b/tests/errors/default-gtype.c-expected
@@ -1,6 +1,13 @@
 /* errors_default_gtype.c generated by valac, the Vala compiler
  * generated from errors_default_gtype.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/errors/delegate-throws-error-code.c-expected b/tests/errors/delegate-throws-error-code.c-expected
index 9848b053513e030e..33d21fa6c6578221 100644
--- a/tests/errors/delegate-throws-error-code.c-expected
+++ b/tests/errors/delegate-throws-error-code.c-expected
@@ -1,6 +1,13 @@
 /* errors_delegate_throws_error_code.c generated by valac, the Vala compiler
  * generated from errors_delegate_throws_error_code.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/errors/errorcode.c-expected b/tests/errors/errorcode.c-expected
index 785b8565a977f55b..cd614b33fd7c31e8 100644
--- a/tests/errors/errorcode.c-expected
+++ b/tests/errors/errorcode.c-expected
@@ -1,6 +1,13 @@
 /* errors_errorcode.c generated by valac, the Vala compiler
  * generated from errors_errorcode.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gio/gio.h>
diff --git a/tests/errors/errordomain-static-method.c-expected b/tests/errors/errordomain-static-method.c-expected
index e18a5f395fb32243..8d182e7ef724e39b 100644
--- a/tests/errors/errordomain-static-method.c-expected
+++ b/tests/errors/errordomain-static-method.c-expected
@@ -1,6 +1,13 @@
 /* errors_errordomain_static_method.c generated by valac, the Vala compiler
  * generated from errors_errordomain_static_method.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <stdlib.h>
diff --git a/tests/errors/errordomain.c-expected b/tests/errors/errordomain.c-expected
index 1f18ffcdd21427a9..070ec7bdaf032c2c 100644
--- a/tests/errors/errordomain.c-expected
+++ b/tests/errors/errordomain.c-expected
@@ -1,6 +1,13 @@
 /* errors_errordomain.c generated by valac, the Vala compiler
  * generated from errors_errordomain.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/errors/errors.c-expected b/tests/errors/errors.c-expected
index d7574a03d1a49d87..21d7fbdbd41c0d97 100644
--- a/tests/errors/errors.c-expected
+++ b/tests/errors/errors.c-expected
@@ -1,6 +1,13 @@
 /* errors_errors.c generated by valac, the Vala compiler
  * generated from errors_errors.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <stdio.h>
diff --git a/tests/errors/loops.c-expected b/tests/errors/loops.c-expected
index 605ac4389d232e8a..02e789c6933f22c1 100644
--- a/tests/errors/loops.c-expected
+++ b/tests/errors/loops.c-expected
@@ -1,6 +1,13 @@
 /* errors_loops.c generated by valac, the Vala compiler
  * generated from errors_loops.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <stdlib.h>
diff --git a/tests/errors/method-throws-error-code.c-expected b/tests/errors/method-throws-error-code.c-expected
index 90ab3eb95194f691..97a36ef5a4778203 100644
--- a/tests/errors/method-throws-error-code.c-expected
+++ b/tests/errors/method-throws-error-code.c-expected
@@ -1,6 +1,13 @@
 /* errors_method_throws_error_code.c generated by valac, the Vala compiler
  * generated from errors_method_throws_error_code.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/errors/method-throws.c-expected b/tests/errors/method-throws.c-expected
index 146c6bceb97f6db3..7602d29949ccb1f0 100644
--- a/tests/errors/method-throws.c-expected
+++ b/tests/errors/method-throws.c-expected
@@ -1,6 +1,13 @@
 /* errors_method_throws.c generated by valac, the Vala compiler
  * generated from errors_method_throws.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/errors/unhandled.c-expected b/tests/errors/unhandled.c-expected
index c5e670413d54b9af..3cf763638d041448 100644
--- a/tests/errors/unhandled.c-expected
+++ b/tests/errors/unhandled.c-expected
@@ -1,6 +1,13 @@
 /* errors_unhandled.c generated by valac, the Vala compiler
  * generated from errors_unhandled.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <stdlib.h>
diff --git a/tests/generics/arrays.c-expected b/tests/generics/arrays.c-expected
index 157f22f429c455d7..00b6a6959984b94a 100644
--- a/tests/generics/arrays.c-expected
+++ b/tests/generics/arrays.c-expected
@@ -1,6 +1,13 @@
 /* generics_arrays.c generated by valac, the Vala compiler
  * generated from generics_arrays.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/generics/bug640330.c-expected b/tests/generics/bug640330.c-expected
index 1c29f40cf49a596c..2a3e0b63d00be8d4 100644
--- a/tests/generics/bug640330.c-expected
+++ b/tests/generics/bug640330.c-expected
@@ -1,6 +1,13 @@
 /* generics_bug640330.c generated by valac, the Vala compiler
  * generated from generics_bug640330.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/generics/bug694765-1.c-expected b/tests/generics/bug694765-1.c-expected
index 221bd42fce3f3045..b06fe4ef59dbfbfb 100644
--- a/tests/generics/bug694765-1.c-expected
+++ b/tests/generics/bug694765-1.c-expected
@@ -1,6 +1,13 @@
 /* generics_bug694765_1.c generated by valac, the Vala compiler
  * generated from generics_bug694765_1.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/generics/bug694765-2.c-expected b/tests/generics/bug694765-2.c-expected
index 1cf5dba069cb9b07..4c9e049f810c0f94 100644
--- a/tests/generics/bug694765-2.c-expected
+++ b/tests/generics/bug694765-2.c-expected
@@ -1,6 +1,13 @@
 /* generics_bug694765_2.c generated by valac, the Vala compiler
  * generated from generics_bug694765_2.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/generics/bug694765-3.c-expected b/tests/generics/bug694765-3.c-expected
index 5dfd97d33cf5954f..5a9edc05e7f136a1 100644
--- a/tests/generics/bug694765-3.c-expected
+++ b/tests/generics/bug694765-3.c-expected
@@ -1,6 +1,13 @@
 /* generics_bug694765_3.c generated by valac, the Vala compiler
  * generated from generics_bug694765_3.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/generics/class-property-override.c-expected b/tests/generics/class-property-override.c-expected
index 02e626ac627166f4..21c4f1010d9afd98 100644
--- a/tests/generics/class-property-override.c-expected
+++ b/tests/generics/class-property-override.c-expected
@@ -1,6 +1,13 @@
 /* generics_class_property_override.c generated by valac, the Vala compiler
  * generated from generics_class_property_override.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/generics/constructor-chain-up.c-expected b/tests/generics/constructor-chain-up.c-expected
index 32a0cef0294ecd5f..537a88065845fad3 100644
--- a/tests/generics/constructor-chain-up.c-expected
+++ b/tests/generics/constructor-chain-up.c-expected
@@ -1,6 +1,13 @@
 /* generics_constructor_chain_up.c generated by valac, the Vala compiler
  * generated from generics_constructor_chain_up.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/generics/floating-type-cast.c-expected b/tests/generics/floating-type-cast.c-expected
index 405a376d9896f400..4882a15d3774c325 100644
--- a/tests/generics/floating-type-cast.c-expected
+++ b/tests/generics/floating-type-cast.c-expected
@@ -1,6 +1,13 @@
 /* generics_floating_type_cast.c generated by valac, the Vala compiler
  * generated from generics_floating_type_cast.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <float.h>
diff --git a/tests/generics/inference-argument-may-fail.c-expected b/tests/generics/inference-argument-may-fail.c-expected
index f4d91abd68f681d1..f46c6312b31623fc 100644
--- a/tests/generics/inference-argument-may-fail.c-expected
+++ b/tests/generics/inference-argument-may-fail.c-expected
@@ -1,6 +1,13 @@
 /* generics_inference_argument_may_fail.c generated by valac, the Vala compiler
  * generated from generics_inference_argument_may_fail.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/generics/inference-static-function.c-expected b/tests/generics/inference-static-function.c-expected
index 25ac2348e13579dc..fc0c5a84d9055010 100644
--- a/tests/generics/inference-static-function.c-expected
+++ b/tests/generics/inference-static-function.c-expected
@@ -1,6 +1,13 @@
 /* generics_inference_static_function.c generated by valac, the Vala compiler
  * generated from generics_inference_static_function.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/generics/integer-member-access.c-expected b/tests/generics/integer-member-access.c-expected
index 19e803fa45be5934..3fb128c51341211d 100644
--- a/tests/generics/integer-member-access.c-expected
+++ b/tests/generics/integer-member-access.c-expected
@@ -1,6 +1,13 @@
 /* generics_integer_member_access.c generated by valac, the Vala compiler
  * generated from generics_integer_member_access.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
 #include <glib.h>
diff --git a/tests/generics/integer-type-cast-return.c-expected b/tests/generics/integer-type-cast-return.c-expected
index 47e1ae95cdd5771a..f7d103b516b2d6c0 100644
--- a/tests/generics/integer-type-cast-return.c-expected
+++ b/tests/generics/integer-type-cast-return.c-expected
@@ -1,6 +1,13 @@
 /* generics_integer_type_cast_return.c generated by valac, the Vala compiler
  * generated from generics_integer_type_cast_return.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/generics/integer-type-cast.c-expected b/tests/generics/integer-type-cast.c-expected
index 35f7fb6bccfd8552..39352346ae501dad 100644
--- a/tests/generics/integer-type-cast.c-expected
+++ b/tests/generics/integer-type-cast.c-expected
@@ -1,6 +1,13 @@
 /* generics_integer_type_cast.c generated by valac, the Vala compiler
  * generated from generics_integer_type_cast.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/generics/interface-property-impl.c-expected b/tests/generics/interface-property-impl.c-expected
index a845e088571af11f..f742b88d47b792b0 100644
--- a/tests/generics/interface-property-impl.c-expected
+++ b/tests/generics/interface-property-impl.c-expected
@@ -1,6 +1,13 @@
 /* generics_interface_property_impl.c generated by valac, the Vala compiler
  * generated from generics_interface_property_impl.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/generics/member-dup-destroy.c-expected b/tests/generics/member-dup-destroy.c-expected
index aba13ad020a5c542..c7a30b52d1d21b95 100644
--- a/tests/generics/member-dup-destroy.c-expected
+++ b/tests/generics/member-dup-destroy.c-expected
@@ -1,6 +1,13 @@
 /* generics_member_dup_destroy.c generated by valac, the Vala compiler
  * generated from generics_member_dup_destroy.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <stdlib.h>
diff --git a/tests/generics/method-return-cast.c-expected b/tests/generics/method-return-cast.c-expected
index 5d1553c74dfc5282..14dd30e0efe2fbc8 100644
--- a/tests/generics/method-return-cast.c-expected
+++ b/tests/generics/method-return-cast.c-expected
@@ -1,6 +1,13 @@
 /* generics_method_return_cast.c generated by valac, the Vala compiler
  * generated from generics_method_return_cast.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <stdlib.h>
diff --git a/tests/generics/null-type.c-expected b/tests/generics/null-type.c-expected
index 3988e36094a76df0..a8d59d062d6820c2 100644
--- a/tests/generics/null-type.c-expected
+++ b/tests/generics/null-type.c-expected
@@ -1,6 +1,13 @@
 /* generics_null_type.c generated by valac, the Vala compiler
  * generated from generics_null_type.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/generics/parameter-in-cast.c-expected b/tests/generics/parameter-in-cast.c-expected
index f5ea0718c72ba268..2bb94cf478ce5940 100644
--- a/tests/generics/parameter-in-cast.c-expected
+++ b/tests/generics/parameter-in-cast.c-expected
@@ -1,6 +1,13 @@
 /* generics_parameter_in_cast.c generated by valac, the Vala compiler
  * generated from generics_parameter_in_cast.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/generics/parameter-out-cast.c-expected b/tests/generics/parameter-out-cast.c-expected
index d43b977b5c339766..cd118f950bd70546 100644
--- a/tests/generics/parameter-out-cast.c-expected
+++ b/tests/generics/parameter-out-cast.c-expected
@@ -1,6 +1,13 @@
 /* generics_parameter_out_cast.c generated by valac, the Vala compiler
  * generated from generics_parameter_out_cast.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/generics/parameter-sizeof-initializer-2.c-expected b/tests/generics/parameter-sizeof-initializer-2.c-expected
index d8de851525de5c27..aa7b0d77a450f9a7 100644
--- a/tests/generics/parameter-sizeof-initializer-2.c-expected
+++ b/tests/generics/parameter-sizeof-initializer-2.c-expected
@@ -1,6 +1,13 @@
 /* generics_parameter_sizeof_initializer_2.c generated by valac, the Vala compiler
  * generated from generics_parameter_sizeof_initializer_2.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/generics/parameter-sizeof-initializer.c-expected b/tests/generics/parameter-sizeof-initializer.c-expected
index cd21eb8d0b64cd12..c0ecf6a131ceb6ae 100644
--- a/tests/generics/parameter-sizeof-initializer.c-expected
+++ b/tests/generics/parameter-sizeof-initializer.c-expected
@@ -1,6 +1,13 @@
 /* generics_parameter_sizeof_initializer.c generated by valac, the Vala compiler
  * generated from generics_parameter_sizeof_initializer.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/generics/parameter-typeof-initializer.c-expected b/tests/generics/parameter-typeof-initializer.c-expected
index 05beefc2f8128f86..46160b0a17fb7d2e 100644
--- a/tests/generics/parameter-typeof-initializer.c-expected
+++ b/tests/generics/parameter-typeof-initializer.c-expected
@@ -1,6 +1,13 @@
 /* generics_parameter_typeof_initializer.c generated by valac, the Vala compiler
  * generated from generics_parameter_typeof_initializer.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/generics/parameter-typeof.c-expected b/tests/generics/parameter-typeof.c-expected
index e13b2b71a4868c93..d89f0425eac96936 100644
--- a/tests/generics/parameter-typeof.c-expected
+++ b/tests/generics/parameter-typeof.c-expected
@@ -1,6 +1,13 @@
 /* generics_parameter_typeof.c generated by valac, the Vala compiler
  * generated from generics_parameter_typeof.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/generics/property-gobject-set.c-expected b/tests/generics/property-gobject-set.c-expected
index 8308f85a8d17d65b..dea75e57e7df51b8 100644
--- a/tests/generics/property-gobject-set.c-expected
+++ b/tests/generics/property-gobject-set.c-expected
@@ -1,6 +1,13 @@
 /* generics_property_gobject_set.c generated by valac, the Vala compiler
  * generated from generics_property_gobject_set.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/generics/property-int-cast.c-expected b/tests/generics/property-int-cast.c-expected
index b2708305aa0b320d..31e93011037b5ef8 100644
--- a/tests/generics/property-int-cast.c-expected
+++ b/tests/generics/property-int-cast.c-expected
@@ -1,6 +1,13 @@
 /* generics_property_int_cast.c generated by valac, the Vala compiler
  * generated from generics_property_int_cast.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/generics/reference-transfer.c-expected b/tests/generics/reference-transfer.c-expected
index e3818a195168a103..ce945a14028a247d 100644
--- a/tests/generics/reference-transfer.c-expected
+++ b/tests/generics/reference-transfer.c-expected
@@ -1,6 +1,13 @@
 /* generics_reference_transfer.c generated by valac, the Vala compiler
  * generated from generics_reference_transfer.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/generics/string-literal-comparison.c-expected b/tests/generics/string-literal-comparison.c-expected
index 4a4222f22b8ceed1..feab42564f604e7b 100644
--- a/tests/generics/string-literal-comparison.c-expected
+++ b/tests/generics/string-literal-comparison.c-expected
@@ -1,6 +1,13 @@
 /* generics_string_literal_comparison.c generated by valac, the Vala compiler
  * generated from generics_string_literal_comparison.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/generics/type-parameter-properties.c-expected b/tests/generics/type-parameter-properties.c-expected
index 263c957a385f6480..c2094c9302644409 100644
--- a/tests/generics/type-parameter-properties.c-expected
+++ b/tests/generics/type-parameter-properties.c-expected
@@ -1,6 +1,13 @@
 /* generics_type_parameter_properties.c generated by valac, the Vala compiler
  * generated from generics_type_parameter_properties.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/generics/type-parameter-property-clash.c-expected b/tests/generics/type-parameter-property-clash.c-expected
index 1f849dfdba464d2c..996c1fa6d98cdff6 100644
--- a/tests/generics/type-parameter-property-clash.c-expected
+++ b/tests/generics/type-parameter-property-clash.c-expected
@@ -1,6 +1,13 @@
 /* generics_type_parameter_property_clash.c generated by valac, the Vala compiler
  * generated from generics_type_parameter_property_clash.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/generics/value-pointer-type-access.c-expected b/tests/generics/value-pointer-type-access.c-expected
index e98d7fa45c09b574..e3cafbc959f03692 100644
--- a/tests/generics/value-pointer-type-access.c-expected
+++ b/tests/generics/value-pointer-type-access.c-expected
@@ -1,6 +1,13 @@
 /* generics_value_pointer_type_access.c generated by valac, the Vala compiler
  * generated from generics_value_pointer_type_access.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/genie/case.c-expected b/tests/genie/case.c-expected
index 5bca8f57c56dcfbe..d6289e2b3b80a93a 100644
--- a/tests/genie/case.c-expected
+++ b/tests/genie/case.c-expected
@@ -1,6 +1,13 @@
 /* genie_case.c generated by valac, the Vala compiler
  * generated from genie_case.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/class-abstract.c-expected b/tests/genie/class-abstract.c-expected
index 68b860a53fe1337e..448c789838809660 100644
--- a/tests/genie/class-abstract.c-expected
+++ b/tests/genie/class-abstract.c-expected
@@ -1,6 +1,13 @@
 /* genie_class_abstract.c generated by valac, the Vala compiler
  * generated from genie_class_abstract.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/class-field.c-expected b/tests/genie/class-field.c-expected
index 18dbc12b52e7b798..c78b5f272ff4dde0 100644
--- a/tests/genie/class-field.c-expected
+++ b/tests/genie/class-field.c-expected
@@ -1,6 +1,13 @@
 /* genie_class_field.c generated by valac, the Vala compiler
  * generated from genie_class_field.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/class-init.c-expected b/tests/genie/class-init.c-expected
index b0cf044bb4bbb572..4e6d2bfa5d14b691 100644
--- a/tests/genie/class-init.c-expected
+++ b/tests/genie/class-init.c-expected
@@ -1,6 +1,13 @@
 /* genie_class_init.c generated by valac, the Vala compiler
  * generated from genie_class_init.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/class-property.c-expected b/tests/genie/class-property.c-expected
index f936f2f7d5149bd7..524668c67681f905 100644
--- a/tests/genie/class-property.c-expected
+++ b/tests/genie/class-property.c-expected
@@ -1,6 +1,13 @@
 /* genie_class_property.c generated by valac, the Vala compiler
  * generated from genie_class_property.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/class-signal.c-expected b/tests/genie/class-signal.c-expected
index 281b12fdf4d190e3..3cdf6ad3bbb52211 100644
--- a/tests/genie/class-signal.c-expected
+++ b/tests/genie/class-signal.c-expected
@@ -1,6 +1,13 @@
 /* genie_class_signal.c generated by valac, the Vala compiler
  * generated from genie_class_signal.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/class.c-expected b/tests/genie/class.c-expected
index f202bc5de4287222..0f46b518a25ae931 100644
--- a/tests/genie/class.c-expected
+++ b/tests/genie/class.c-expected
@@ -1,6 +1,13 @@
 /* genie_class.c generated by valac, the Vala compiler
  * generated from genie_class.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/constant.c-expected b/tests/genie/constant.c-expected
index 24099c0fc4011f9c..0d5e70860cc81e54 100644
--- a/tests/genie/constant.c-expected
+++ b/tests/genie/constant.c-expected
@@ -1,6 +1,13 @@
 /* genie_constant.c generated by valac, the Vala compiler
  * generated from genie_constant.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/control-flow-if-do.c-expected b/tests/genie/control-flow-if-do.c-expected
index e12b668654b64db2..2b5b231cbe366483 100644
--- a/tests/genie/control-flow-if-do.c-expected
+++ b/tests/genie/control-flow-if-do.c-expected
@@ -1,6 +1,13 @@
 /* genie_control_flow_if_do.c generated by valac, the Vala compiler
  * generated from genie_control_flow_if_do.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/control-flow-if-else-if.c-expected b/tests/genie/control-flow-if-else-if.c-expected
index 41ed9beb40f4cb38..0739eff920e6c56b 100644
--- a/tests/genie/control-flow-if-else-if.c-expected
+++ b/tests/genie/control-flow-if-else-if.c-expected
@@ -1,6 +1,13 @@
 /* genie_control_flow_if_else_if.c generated by valac, the Vala compiler
  * generated from genie_control_flow_if_else_if.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/control-flow-if-else.c-expected b/tests/genie/control-flow-if-else.c-expected
index 2662e5d1cd2613b6..a76309771e158c7e 100644
--- a/tests/genie/control-flow-if-else.c-expected
+++ b/tests/genie/control-flow-if-else.c-expected
@@ -1,6 +1,13 @@
 /* genie_control_flow_if_else.c generated by valac, the Vala compiler
  * generated from genie_control_flow_if_else.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/control-flow-if-greater-than.c-expected b/tests/genie/control-flow-if-greater-than.c-expected
index d9c9a21462497f47..fd63150b17c6c2ee 100644
--- a/tests/genie/control-flow-if-greater-than.c-expected
+++ b/tests/genie/control-flow-if-greater-than.c-expected
@@ -1,6 +1,13 @@
 /* genie_control_flow_if_greater_than.c generated by valac, the Vala compiler
  * generated from genie_control_flow_if_greater_than.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/control-flow-if-identity.c-expected b/tests/genie/control-flow-if-identity.c-expected
index a8f2b2bc4562c692..aa3badb91607b5c9 100644
--- a/tests/genie/control-flow-if-identity.c-expected
+++ b/tests/genie/control-flow-if-identity.c-expected
@@ -1,6 +1,13 @@
 /* genie_control_flow_if_identity.c generated by valac, the Vala compiler
  * generated from genie_control_flow_if_identity.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/control-flow-if-less-than.c-expected b/tests/genie/control-flow-if-less-than.c-expected
index ad03ce963b00a399..7ae7de22eb9f99c8 100644
--- a/tests/genie/control-flow-if-less-than.c-expected
+++ b/tests/genie/control-flow-if-less-than.c-expected
@@ -1,6 +1,13 @@
 /* genie_control_flow_if_less_than.c generated by valac, the Vala compiler
  * generated from genie_control_flow_if_less_than.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/control-flow-if.c-expected b/tests/genie/control-flow-if.c-expected
index 749c45ce78f1e59f..8e7da2d1e995eb7e 100644
--- a/tests/genie/control-flow-if.c-expected
+++ b/tests/genie/control-flow-if.c-expected
@@ -1,6 +1,13 @@
 /* genie_control_flow_if.c generated by valac, the Vala compiler
  * generated from genie_control_flow_if.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/do-while.c-expected b/tests/genie/do-while.c-expected
index d5f3c5fd85236a6f..88ff0774a22cda44 100644
--- a/tests/genie/do-while.c-expected
+++ b/tests/genie/do-while.c-expected
@@ -1,6 +1,13 @@
 /* genie_do_while.c generated by valac, the Vala compiler
  * generated from genie_do_while.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/enum-with-keyword-values.c-expected b/tests/genie/enum-with-keyword-values.c-expected
index 73251008d32d3eee..dd5887e8b5b5ec90 100644
--- a/tests/genie/enum-with-keyword-values.c-expected
+++ b/tests/genie/enum-with-keyword-values.c-expected
@@ -1,6 +1,13 @@
 /* genie_enum_with_keyword_values.c generated by valac, the Vala compiler
  * generated from genie_enum_with_keyword_values.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/enum.c-expected b/tests/genie/enum.c-expected
index 4e82a099d976af79..2d45b377ebf7a9ab 100644
--- a/tests/genie/enum.c-expected
+++ b/tests/genie/enum.c-expected
@@ -1,6 +1,13 @@
 /* genie_enum.c generated by valac, the Vala compiler
  * generated from genie_enum.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/exception.c-expected b/tests/genie/exception.c-expected
index 269d7925e6a96710..7f96ba0d36550e13 100644
--- a/tests/genie/exception.c-expected
+++ b/tests/genie/exception.c-expected
@@ -1,6 +1,13 @@
 /* genie_exception.c generated by valac, the Vala compiler
  * generated from genie_exception.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/for-downto.c-expected b/tests/genie/for-downto.c-expected
index e286dbadae510236..fd7b0ac82de2e984 100644
--- a/tests/genie/for-downto.c-expected
+++ b/tests/genie/for-downto.c-expected
@@ -1,6 +1,13 @@
 /* genie_for_downto.c generated by valac, the Vala compiler
  * generated from genie_for_downto.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/for-in.c-expected b/tests/genie/for-in.c-expected
index 461ae185e10a005d..4293e24e92b85a5f 100644
--- a/tests/genie/for-in.c-expected
+++ b/tests/genie/for-in.c-expected
@@ -1,6 +1,13 @@
 /* genie_for_in.c generated by valac, the Vala compiler
  * generated from genie_for_in.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/for-to.c-expected b/tests/genie/for-to.c-expected
index 5b3cf80f3f088e10..f7ccfc1e410e0544 100644
--- a/tests/genie/for-to.c-expected
+++ b/tests/genie/for-to.c-expected
@@ -1,6 +1,13 @@
 /* genie_for_to.c generated by valac, the Vala compiler
  * generated from genie_for_to.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/function-returns-closure.c-expected b/tests/genie/function-returns-closure.c-expected
index d3e148330dfa7acc..6b7aa3267df87693 100644
--- a/tests/genie/function-returns-closure.c-expected
+++ b/tests/genie/function-returns-closure.c-expected
@@ -1,6 +1,13 @@
 /* genie_function_returns_closure.c generated by valac, the Vala compiler
  * generated from genie_function_returns_closure.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/genie/function-with-argument.c-expected b/tests/genie/function-with-argument.c-expected
index fc6293b798894faf..2146a1bf874352b4 100644
--- a/tests/genie/function-with-argument.c-expected
+++ b/tests/genie/function-with-argument.c-expected
@@ -1,6 +1,13 @@
 /* genie_function_with_argument.c generated by valac, the Vala compiler
  * generated from genie_function_with_argument.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/function-with-return-value.c-expected b/tests/genie/function-with-return-value.c-expected
index 15b6a81091892083..d9a54a9b5a21982e 100644
--- a/tests/genie/function-with-return-value.c-expected
+++ b/tests/genie/function-with-return-value.c-expected
@@ -1,6 +1,13 @@
 /* genie_function_with_return_value.c generated by valac, the Vala compiler
  * generated from genie_function_with_return_value.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/function.c-expected b/tests/genie/function.c-expected
index f3955085dcc4b891..6f6389d1ddd62bda 100644
--- a/tests/genie/function.c-expected
+++ b/tests/genie/function.c-expected
@@ -1,6 +1,13 @@
 /* genie_function.c generated by valac, the Vala compiler
  * generated from genie_function.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/genie/indentation-with-spaces.c-expected b/tests/genie/indentation-with-spaces.c-expected
index a157ee9930e73898..2f359bcf99c9691d 100644
--- a/tests/genie/indentation-with-spaces.c-expected
+++ b/tests/genie/indentation-with-spaces.c-expected
@@ -1,6 +1,13 @@
 /* genie_indentation_with_spaces.c generated by valac, the Vala compiler
  * generated from genie_indentation_with_spaces.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/init-int.c-expected b/tests/genie/init-int.c-expected
index 745372794a5b8fa0..5a0c06621e912a4e 100644
--- a/tests/genie/init-int.c-expected
+++ b/tests/genie/init-int.c-expected
@@ -1,6 +1,13 @@
 /* genie_init_int.c generated by valac, the Vala compiler
  * generated from genie_init_int.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/init.c-expected b/tests/genie/init.c-expected
index e97f519df931050b..0ca12727d56f50ae 100644
--- a/tests/genie/init.c-expected
+++ b/tests/genie/init.c-expected
@@ -1,6 +1,13 @@
 /* genie_init.c generated by valac, the Vala compiler
  * generated from genie_init.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/initializer-list.c-expected b/tests/genie/initializer-list.c-expected
index 9bc4e7bafeee2fdf..998cd3b24eb727a6 100644
--- a/tests/genie/initializer-list.c-expected
+++ b/tests/genie/initializer-list.c-expected
@@ -1,6 +1,13 @@
 /* genie_initializer_list.c generated by valac, the Vala compiler
  * generated from genie_initializer_list.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/interface.c-expected b/tests/genie/interface.c-expected
index 3a8087f1aa5ea443..065028ce8a281932 100644
--- a/tests/genie/interface.c-expected
+++ b/tests/genie/interface.c-expected
@@ -1,6 +1,13 @@
 /* genie_interface.c generated by valac, the Vala compiler
  * generated from genie_interface.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/literal-boolean-assignment.c-expected b/tests/genie/literal-boolean-assignment.c-expected
index 77b90dc18af308c1..5543cef98efcb534 100644
--- a/tests/genie/literal-boolean-assignment.c-expected
+++ b/tests/genie/literal-boolean-assignment.c-expected
@@ -1,6 +1,13 @@
 /* genie_literal_boolean_assignment.c generated by valac, the Vala compiler
  * generated from genie_literal_boolean_assignment.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/literal-boolean.c-expected b/tests/genie/literal-boolean.c-expected
index 4d04b24e85ab4052..ca0b01148527b9d7 100644
--- a/tests/genie/literal-boolean.c-expected
+++ b/tests/genie/literal-boolean.c-expected
@@ -1,6 +1,13 @@
 /* genie_literal_boolean.c generated by valac, the Vala compiler
  * generated from genie_literal_boolean.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/literal-character.c-expected b/tests/genie/literal-character.c-expected
index 3a8e35e6f3cdb5f5..b4b53b74d625290f 100644
--- a/tests/genie/literal-character.c-expected
+++ b/tests/genie/literal-character.c-expected
@@ -1,6 +1,13 @@
 /* genie_literal_character.c generated by valac, the Vala compiler
  * generated from genie_literal_character.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/literal-hexadecimal.c-expected b/tests/genie/literal-hexadecimal.c-expected
index f7098075db368d64..9545dcfb0c07aa29 100644
--- a/tests/genie/literal-hexadecimal.c-expected
+++ b/tests/genie/literal-hexadecimal.c-expected
@@ -1,6 +1,13 @@
 /* genie_literal_hexadecimal.c generated by valac, the Vala compiler
  * generated from genie_literal_hexadecimal.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/literal-integer-long-long-suffix.c-expected b/tests/genie/literal-integer-long-long-suffix.c-expected
index ad71e61dce4b5a71..eca2f8bb93de4eda 100644
--- a/tests/genie/literal-integer-long-long-suffix.c-expected
+++ b/tests/genie/literal-integer-long-long-suffix.c-expected
@@ -1,6 +1,13 @@
 /* genie_literal_integer_long_long_suffix.c generated by valac, the Vala compiler
  * generated from genie_literal_integer_long_long_suffix.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/literal-integer.c-expected b/tests/genie/literal-integer.c-expected
index 1f94181037ab13d6..a07323ace1e614c0 100644
--- a/tests/genie/literal-integer.c-expected
+++ b/tests/genie/literal-integer.c-expected
@@ -1,6 +1,13 @@
 /* genie_literal_integer.c generated by valac, the Vala compiler
  * generated from genie_literal_integer.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/literal-null.c-expected b/tests/genie/literal-null.c-expected
index 822f14b263b00a23..1fd43dccc12b4941 100644
--- a/tests/genie/literal-null.c-expected
+++ b/tests/genie/literal-null.c-expected
@@ -1,6 +1,13 @@
 /* genie_literal_null.c generated by valac, the Vala compiler
  * generated from genie_literal_null.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/literal-octal.c-expected b/tests/genie/literal-octal.c-expected
index 8feeb804ce397ebe..1cc326f877a8a155 100644
--- a/tests/genie/literal-octal.c-expected
+++ b/tests/genie/literal-octal.c-expected
@@ -1,6 +1,13 @@
 /* genie_literal_octal.c generated by valac, the Vala compiler
  * generated from genie_literal_octal.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/literal-real.c-expected b/tests/genie/literal-real.c-expected
index 2d6a8c7d64130e08..8d27cbc2ba0afba3 100644
--- a/tests/genie/literal-real.c-expected
+++ b/tests/genie/literal-real.c-expected
@@ -1,6 +1,13 @@
 /* genie_literal_real.c generated by valac, the Vala compiler
  * generated from genie_literal_real.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/literal-regex.c-expected b/tests/genie/literal-regex.c-expected
index 2c3496e4aaf46786..a8025d9736f38723 100644
--- a/tests/genie/literal-regex.c-expected
+++ b/tests/genie/literal-regex.c-expected
@@ -1,6 +1,13 @@
 /* genie_literal_regex.c generated by valac, the Vala compiler
  * generated from genie_literal_regex.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/literal-template-string.c-expected b/tests/genie/literal-template-string.c-expected
index 9dad5e4320003503..6eddb7e044b08761 100644
--- a/tests/genie/literal-template-string.c-expected
+++ b/tests/genie/literal-template-string.c-expected
@@ -1,6 +1,13 @@
 /* genie_literal_template_string.c generated by valac, the Vala compiler
  * generated from genie_literal_template_string.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/literal-verbatim-string.c-expected b/tests/genie/literal-verbatim-string.c-expected
index d10367a7a74e3d16..f8604c0e407d6c3c 100644
--- a/tests/genie/literal-verbatim-string.c-expected
+++ b/tests/genie/literal-verbatim-string.c-expected
@@ -1,6 +1,13 @@
 /* genie_literal_verbatim_string.c generated by valac, the Vala compiler
  * generated from genie_literal_verbatim_string.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-addition.c-expected b/tests/genie/operator-addition.c-expected
index 867d27f058b12dc5..1f431dd5f435f448 100644
--- a/tests/genie/operator-addition.c-expected
+++ b/tests/genie/operator-addition.c-expected
@@ -1,6 +1,13 @@
 /* genie_operator_addition.c generated by valac, the Vala compiler
  * generated from genie_operator_addition.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-assignment-combined.c-expected b/tests/genie/operator-assignment-combined.c-expected
index f92f2010b2a254f2..392237391cd09a5e 100644
--- a/tests/genie/operator-assignment-combined.c-expected
+++ b/tests/genie/operator-assignment-combined.c-expected
@@ -1,6 +1,13 @@
 /* genie_operator_assignment_combined.c generated by valac, the Vala compiler
  * generated from genie_operator_assignment_combined.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-assignment.c-expected b/tests/genie/operator-assignment.c-expected
index 39020a6c4e01e69a..fd769207fb6f7b19 100644
--- a/tests/genie/operator-assignment.c-expected
+++ b/tests/genie/operator-assignment.c-expected
@@ -1,6 +1,13 @@
 /* genie_operator_assignment.c generated by valac, the Vala compiler
  * generated from genie_operator_assignment.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-bitwise-and.c-expected b/tests/genie/operator-bitwise-and.c-expected
index cb7dc1850a616c9a..3f58bea7de2fc22f 100644
--- a/tests/genie/operator-bitwise-and.c-expected
+++ b/tests/genie/operator-bitwise-and.c-expected
@@ -1,6 +1,13 @@
 /* genie_operator_bitwise_and.c generated by valac, the Vala compiler
  * generated from genie_operator_bitwise_and.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-bitwise-left-shift.c-expected b/tests/genie/operator-bitwise-left-shift.c-expected
index 79aa349c9b1ef20a..075e6d6d6733385a 100644
--- a/tests/genie/operator-bitwise-left-shift.c-expected
+++ b/tests/genie/operator-bitwise-left-shift.c-expected
@@ -1,6 +1,13 @@
 /* genie_operator_bitwise_left_shift.c generated by valac, the Vala compiler
  * generated from genie_operator_bitwise_left_shift.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-bitwise-not.c-expected b/tests/genie/operator-bitwise-not.c-expected
index 526bc2dd6d319743..3cc0ff4ab46749cb 100644
--- a/tests/genie/operator-bitwise-not.c-expected
+++ b/tests/genie/operator-bitwise-not.c-expected
@@ -1,6 +1,13 @@
 /* genie_operator_bitwise_not.c generated by valac, the Vala compiler
  * generated from genie_operator_bitwise_not.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-bitwise-or.c-expected b/tests/genie/operator-bitwise-or.c-expected
index d14ba9f53cd7416f..7384a408060de948 100644
--- a/tests/genie/operator-bitwise-or.c-expected
+++ b/tests/genie/operator-bitwise-or.c-expected
@@ -1,6 +1,13 @@
 /* genie_operator_bitwise_or.c generated by valac, the Vala compiler
  * generated from genie_operator_bitwise_or.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-bitwise-right-shift.c-expected b/tests/genie/operator-bitwise-right-shift.c-expected
index c0700350eb6b90c8..48e57b8b7cd4f2ce 100644
--- a/tests/genie/operator-bitwise-right-shift.c-expected
+++ b/tests/genie/operator-bitwise-right-shift.c-expected
@@ -1,6 +1,13 @@
 /* genie_operator_bitwise_right_shift.c generated by valac, the Vala compiler
  * generated from genie_operator_bitwise_right_shift.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-bitwise-xor.c-expected b/tests/genie/operator-bitwise-xor.c-expected
index 6a8db99dc92e874b..55227bb7391fe41e 100644
--- a/tests/genie/operator-bitwise-xor.c-expected
+++ b/tests/genie/operator-bitwise-xor.c-expected
@@ -1,6 +1,13 @@
 /* genie_operator_bitwise_xor.c generated by valac, the Vala compiler
  * generated from genie_operator_bitwise_xor.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-division.c-expected b/tests/genie/operator-division.c-expected
index edcf3054105159f4..0b2af41eba6fb883 100644
--- a/tests/genie/operator-division.c-expected
+++ b/tests/genie/operator-division.c-expected
@@ -1,6 +1,13 @@
 /* genie_operator_division.c generated by valac, the Vala compiler
  * generated from genie_operator_division.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-equal.c-expected b/tests/genie/operator-equal.c-expected
index c481f40cf7474faf..9018f28ecdd7ac5b 100644
--- a/tests/genie/operator-equal.c-expected
+++ b/tests/genie/operator-equal.c-expected
@@ -1,6 +1,13 @@
 /* genie_operator_equal.c generated by valac, the Vala compiler
  * generated from genie_operator_equal.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-greater-than-equal.c-expected b/tests/genie/operator-greater-than-equal.c-expected
index 20c23ce144c0d6dc..e6f28140ed087969 100644
--- a/tests/genie/operator-greater-than-equal.c-expected
+++ b/tests/genie/operator-greater-than-equal.c-expected
@@ -1,6 +1,13 @@
 /* genie_operator_greater_than_equal.c generated by valac, the Vala compiler
  * generated from genie_operator_greater_than_equal.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-less-than-equal.c-expected b/tests/genie/operator-less-than-equal.c-expected
index 8d742948c47c48c8..23e852b8f914cab4 100644
--- a/tests/genie/operator-less-than-equal.c-expected
+++ b/tests/genie/operator-less-than-equal.c-expected
@@ -1,6 +1,13 @@
 /* genie_operator_less_than_equal.c generated by valac, the Vala compiler
  * generated from genie_operator_less_than_equal.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-less-than.c-expected b/tests/genie/operator-less-than.c-expected
index 7996517c21db0c68..70363b4a3372e56d 100644
--- a/tests/genie/operator-less-than.c-expected
+++ b/tests/genie/operator-less-than.c-expected
@@ -1,6 +1,13 @@
 /* genie_operator_less_than.c generated by valac, the Vala compiler
  * generated from genie_operator_less_than.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-logical-and.c-expected b/tests/genie/operator-logical-and.c-expected
index ee0de64b62e891a5..ff50ac794fce4a05 100644
--- a/tests/genie/operator-logical-and.c-expected
+++ b/tests/genie/operator-logical-and.c-expected
@@ -1,6 +1,13 @@
 /* genie_operator_logical_and.c generated by valac, the Vala compiler
  * generated from genie_operator_logical_and.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-logical-not.c-expected b/tests/genie/operator-logical-not.c-expected
index 0113033030f1f534..3a355354d284a2aa 100644
--- a/tests/genie/operator-logical-not.c-expected
+++ b/tests/genie/operator-logical-not.c-expected
@@ -1,6 +1,13 @@
 /* genie_operator_logical_not.c generated by valac, the Vala compiler
  * generated from genie_operator_logical_not.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-logical-or.c-expected b/tests/genie/operator-logical-or.c-expected
index d90e3dfad6b343a3..ca2bc6cf4314bba0 100644
--- a/tests/genie/operator-logical-or.c-expected
+++ b/tests/genie/operator-logical-or.c-expected
@@ -1,6 +1,13 @@
 /* genie_operator_logical_or.c generated by valac, the Vala compiler
  * generated from genie_operator_logical_or.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-modulo.c-expected b/tests/genie/operator-modulo.c-expected
index 23560bdb6b164763..4c0cd5f409f26b2e 100644
--- a/tests/genie/operator-modulo.c-expected
+++ b/tests/genie/operator-modulo.c-expected
@@ -1,6 +1,13 @@
 /* genie_operator_modulo.c generated by valac, the Vala compiler
  * generated from genie_operator_modulo.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-multiply.c-expected b/tests/genie/operator-multiply.c-expected
index ec60325786861e7c..321e31f2b8d61308 100644
--- a/tests/genie/operator-multiply.c-expected
+++ b/tests/genie/operator-multiply.c-expected
@@ -1,6 +1,13 @@
 /* genie_operator_multiply.c generated by valac, the Vala compiler
  * generated from genie_operator_multiply.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-not-equal.c-expected b/tests/genie/operator-not-equal.c-expected
index 35b3326c5a295467..4dd29bf408fe52fd 100644
--- a/tests/genie/operator-not-equal.c-expected
+++ b/tests/genie/operator-not-equal.c-expected
@@ -1,6 +1,13 @@
 /* genie_operator_not_equal.c generated by valac, the Vala compiler
  * generated from genie_operator_not_equal.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-post-decrement.c-expected b/tests/genie/operator-post-decrement.c-expected
index 855e924018c08b2e..57a50d99ec632b29 100644
--- a/tests/genie/operator-post-decrement.c-expected
+++ b/tests/genie/operator-post-decrement.c-expected
@@ -1,6 +1,13 @@
 /* genie_operator_post_decrement.c generated by valac, the Vala compiler
  * generated from genie_operator_post_decrement.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-post-increment.c-expected b/tests/genie/operator-post-increment.c-expected
index 3ff86cfb794ee14e..cbff75c5f3871860 100644
--- a/tests/genie/operator-post-increment.c-expected
+++ b/tests/genie/operator-post-increment.c-expected
@@ -1,6 +1,13 @@
 /* genie_operator_post_increment.c generated by valac, the Vala compiler
  * generated from genie_operator_post_increment.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-pre-decrement.c-expected b/tests/genie/operator-pre-decrement.c-expected
index 3841761c627c68a3..6a8b944e1a3fd25f 100644
--- a/tests/genie/operator-pre-decrement.c-expected
+++ b/tests/genie/operator-pre-decrement.c-expected
@@ -1,6 +1,13 @@
 /* genie_operator_pre_decrement.c generated by valac, the Vala compiler
  * generated from genie_operator_pre_decrement.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-pre-increment.c-expected b/tests/genie/operator-pre-increment.c-expected
index d02e3b06bb9d5a79..051b15caab213dd2 100644
--- a/tests/genie/operator-pre-increment.c-expected
+++ b/tests/genie/operator-pre-increment.c-expected
@@ -1,6 +1,13 @@
 /* genie_operator_pre_increment.c generated by valac, the Vala compiler
  * generated from genie_operator_pre_increment.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-subtraction.c-expected b/tests/genie/operator-subtraction.c-expected
index b5cbf4fe63307165..50d4ec23d579fd34 100644
--- a/tests/genie/operator-subtraction.c-expected
+++ b/tests/genie/operator-subtraction.c-expected
@@ -1,6 +1,13 @@
 /* genie_operator_subtraction.c generated by valac, the Vala compiler
  * generated from genie_operator_subtraction.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-ternary.c-expected b/tests/genie/operator-ternary.c-expected
index e22d41c8d0da5b01..fa3302bce1aa5790 100644
--- a/tests/genie/operator-ternary.c-expected
+++ b/tests/genie/operator-ternary.c-expected
@@ -1,6 +1,13 @@
 /* genie_operator_ternary.c generated by valac, the Vala compiler
  * generated from genie_operator_ternary.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operators-greater-than.c-expected b/tests/genie/operators-greater-than.c-expected
index 85d707767486efe0..ade92e6b3fec9908 100644
--- a/tests/genie/operators-greater-than.c-expected
+++ b/tests/genie/operators-greater-than.c-expected
@@ -1,6 +1,13 @@
 /* genie_operators_greater_than.c generated by valac, the Vala compiler
  * generated from genie_operators_greater_than.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/preparser-and-expression.c-expected b/tests/genie/preparser-and-expression.c-expected
index b1c2e293b2fca0a8..91514511c6746acb 100644
--- a/tests/genie/preparser-and-expression.c-expected
+++ b/tests/genie/preparser-and-expression.c-expected
@@ -1,6 +1,13 @@
 /* genie_preparser_and_expression.c generated by valac, the Vala compiler
  * generated from genie_preparser_and_expression.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/preparser-elif.c-expected b/tests/genie/preparser-elif.c-expected
index 785a90927f0691a8..ee1b5d1f6bc33e19 100644
--- a/tests/genie/preparser-elif.c-expected
+++ b/tests/genie/preparser-elif.c-expected
@@ -1,6 +1,13 @@
 /* genie_preparser_elif.c generated by valac, the Vala compiler
  * generated from genie_preparser_elif.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/preparser-equality-expression.c-expected b/tests/genie/preparser-equality-expression.c-expected
index fced1071e9f895a2..7f95970023aa5d6a 100644
--- a/tests/genie/preparser-equality-expression.c-expected
+++ b/tests/genie/preparser-equality-expression.c-expected
@@ -1,6 +1,13 @@
 /* genie_preparser_equality_expression.c generated by valac, the Vala compiler
  * generated from genie_preparser_equality_expression.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/preparser-not.c-expected b/tests/genie/preparser-not.c-expected
index ddc0b1e91848f25d..a0f1c2df0d86dc42 100644
--- a/tests/genie/preparser-not.c-expected
+++ b/tests/genie/preparser-not.c-expected
@@ -1,6 +1,13 @@
 /* genie_preparser_not.c generated by valac, the Vala compiler
  * generated from genie_preparser_not.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/preparser-or-expression.c-expected b/tests/genie/preparser-or-expression.c-expected
index 0967bc9b715d62f9..a4c1822105bbf662 100644
--- a/tests/genie/preparser-or-expression.c-expected
+++ b/tests/genie/preparser-or-expression.c-expected
@@ -1,6 +1,13 @@
 /* genie_preparser_or_expression.c generated by valac, the Vala compiler
  * generated from genie_preparser_or_expression.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/preparser.c-expected b/tests/genie/preparser.c-expected
index a472a63b0cfbc430..52eea981298dd229 100644
--- a/tests/genie/preparser.c-expected
+++ b/tests/genie/preparser.c-expected
@@ -1,6 +1,13 @@
 /* genie_preparser.c generated by valac, the Vala compiler
  * generated from genie_preparser.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/print.c-expected b/tests/genie/print.c-expected
index d74c80c1ee495595..dc21966af6da90c6 100644
--- a/tests/genie/print.c-expected
+++ b/tests/genie/print.c-expected
@@ -1,6 +1,13 @@
 /* genie_print.c generated by valac, the Vala compiler
  * generated from genie_print.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/sizeof.c-expected b/tests/genie/sizeof.c-expected
index 18c1deaac9883d0d..bd8db0ac2306b21e 100644
--- a/tests/genie/sizeof.c-expected
+++ b/tests/genie/sizeof.c-expected
@@ -1,6 +1,13 @@
 /* genie_sizeof.c generated by valac, the Vala compiler
  * generated from genie_sizeof.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/struct-after-class.c-expected b/tests/genie/struct-after-class.c-expected
index 7047db9ad38b5654..f4a5442b51eef0d8 100644
--- a/tests/genie/struct-after-class.c-expected
+++ b/tests/genie/struct-after-class.c-expected
@@ -1,6 +1,13 @@
 /* genie_struct_after_class.c generated by valac, the Vala compiler
  * generated from genie_struct_after_class.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/struct.c-expected b/tests/genie/struct.c-expected
index 9d4e4cb504d527b0..98a73eaac63afeb9 100644
--- a/tests/genie/struct.c-expected
+++ b/tests/genie/struct.c-expected
@@ -1,6 +1,13 @@
 /* genie_struct.c generated by valac, the Vala compiler
  * generated from genie_struct.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/try-except-finally.c-expected b/tests/genie/try-except-finally.c-expected
index 4c945480dbb6d65c..96323e266f9c790f 100644
--- a/tests/genie/try-except-finally.c-expected
+++ b/tests/genie/try-except-finally.c-expected
@@ -1,6 +1,13 @@
 /* genie_try_except_finally.c generated by valac, the Vala compiler
  * generated from genie_try_except_finally.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <gio/gio.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/genie/typeof.c-expected b/tests/genie/typeof.c-expected
index 0428b636baed7835..58393e9d0501ceb9 100644
--- a/tests/genie/typeof.c-expected
+++ b/tests/genie/typeof.c-expected
@@ -1,6 +1,13 @@
 /* genie_typeof.c generated by valac, the Vala compiler
  * generated from genie_typeof.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/while.c-expected b/tests/genie/while.c-expected
index 42a2f172f074da3c..8d781777955a53f2 100644
--- a/tests/genie/while.c-expected
+++ b/tests/genie/while.c-expected
@@ -1,6 +1,13 @@
 /* genie_while.c generated by valac, the Vala compiler
  * generated from genie_while.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/headers/sealed-class.c-expected b/tests/headers/sealed-class.c-expected
index 579a68cdfff47d2d..bdc641daae22488b 100644
--- a/tests/headers/sealed-class.c-expected
+++ b/tests/headers/sealed-class.c-expected
@@ -1,6 +1,13 @@
 /* headers_sealed_class.c generated by valac, the Vala compiler
  * generated from headers_sealed_class.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include "test.h"
 #include <glib.h>
 #include <glib-object.h>
diff --git a/tests/linux/bug793444.c-expected b/tests/linux/bug793444.c-expected
index 0d4973b08113248a..d8ef8a16e98a911b 100644
--- a/tests/linux/bug793444.c-expected
+++ b/tests/linux/bug793444.c-expected
@@ -1,6 +1,13 @@
 /* linux_bug793444.c generated by valac, the Vala compiler
  * generated from linux_bug793444.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #define _GNU_SOURCE
 
 #include <glib.h>
diff --git a/tests/linux/file-commandpipe.c-expected b/tests/linux/file-commandpipe.c-expected
index be210e2a6d91479e..76c4886ac900e062 100644
--- a/tests/linux/file-commandpipe.c-expected
+++ b/tests/linux/file-commandpipe.c-expected
@@ -1,6 +1,13 @@
 /* linux_file_commandpipe.c generated by valac, the Vala compiler
  * generated from linux_file_commandpipe.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdio.h>
 #include <glib.h>
 
diff --git a/tests/methods/argument-array-initilizer.c-expected b/tests/methods/argument-array-initilizer.c-expected
index 9fb7a9ab0e12713a..81caaf8e2d6a7dba 100644
--- a/tests/methods/argument-array-initilizer.c-expected
+++ b/tests/methods/argument-array-initilizer.c-expected
@@ -1,6 +1,13 @@
 /* methods_argument_array_initilizer.c generated by valac, the Vala compiler
  * generated from methods_argument_array_initilizer.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/methods/argument-named.c-expected b/tests/methods/argument-named.c-expected
index ae239b7f1145381f..9c37340e8d95725e 100644
--- a/tests/methods/argument-named.c-expected
+++ b/tests/methods/argument-named.c-expected
@@ -1,6 +1,13 @@
 /* methods_argument_named.c generated by valac, the Vala compiler
  * generated from methods_argument_named.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdarg.h>
diff --git a/tests/methods/array-length-type.c-expected b/tests/methods/array-length-type.c-expected
index 89d97931b2627576..55598053b545e42e 100644
--- a/tests/methods/array-length-type.c-expected
+++ b/tests/methods/array-length-type.c-expected
@@ -1,6 +1,13 @@
 /* methods_array_length_type.c generated by valac, the Vala compiler
  * generated from methods_array_length_type.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/methods/bug540483.c-expected b/tests/methods/bug540483.c-expected
index 5dc573fbe093f724..158be42008d2ee88 100644
--- a/tests/methods/bug540483.c-expected
+++ b/tests/methods/bug540483.c-expected
@@ -1,6 +1,13 @@
 /* methods_bug540483.c generated by valac, the Vala compiler
  * generated from methods_bug540483.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/methods/bug595538.c-expected b/tests/methods/bug595538.c-expected
index 4cca222a129baaef..35c4c440b9b0b2e6 100644
--- a/tests/methods/bug595538.c-expected
+++ b/tests/methods/bug595538.c-expected
@@ -1,6 +1,13 @@
 /* methods_bug595538.c generated by valac, the Vala compiler
  * generated from methods_bug595538.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/methods/bug596726.c-expected b/tests/methods/bug596726.c-expected
index 6fa956d62ebb2613..589a29e1f21f63fa 100644
--- a/tests/methods/bug596726.c-expected
+++ b/tests/methods/bug596726.c-expected
@@ -1,6 +1,13 @@
 /* methods_bug596726.c generated by valac, the Vala compiler
  * generated from methods_bug596726.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/methods/bug597426.c-expected b/tests/methods/bug597426.c-expected
index f13a810576e28a44..12afdaf85927fa71 100644
--- a/tests/methods/bug597426.c-expected
+++ b/tests/methods/bug597426.c-expected
@@ -1,6 +1,13 @@
 /* methods_bug597426.c generated by valac, the Vala compiler
  * generated from methods_bug597426.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/methods/bug598738.c-expected b/tests/methods/bug598738.c-expected
index 8eb818bcc4d9ec16..de110ee3582cc228 100644
--- a/tests/methods/bug598738.c-expected
+++ b/tests/methods/bug598738.c-expected
@@ -1,6 +1,13 @@
 /* methods_bug598738.c generated by valac, the Vala compiler
  * generated from methods_bug598738.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 typedef void (*Func) (gpointer user_data);
diff --git a/tests/methods/bug599892.c-expected b/tests/methods/bug599892.c-expected
index ea79e50fad555848..e83c7f51ed7f63ec 100644
--- a/tests/methods/bug599892.c-expected
+++ b/tests/methods/bug599892.c-expected
@@ -1,6 +1,13 @@
 /* methods_bug599892.c generated by valac, the Vala compiler
  * generated from methods_bug599892.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/methods/bug613483.c-expected b/tests/methods/bug613483.c-expected
index 77c03269e274922c..83b19e900cbda88e 100644
--- a/tests/methods/bug613483.c-expected
+++ b/tests/methods/bug613483.c-expected
@@ -1,6 +1,13 @@
 /* methods_bug613483.c generated by valac, the Vala compiler
  * generated from methods_bug613483.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/methods/bug620673.c-expected b/tests/methods/bug620673.c-expected
index 248cfcef02188938..6975930711ce2db5 100644
--- a/tests/methods/bug620673.c-expected
+++ b/tests/methods/bug620673.c-expected
@@ -1,6 +1,13 @@
 /* methods_bug620673.c generated by valac, the Vala compiler
  * generated from methods_bug620673.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <stdarg.h>
 #include <float.h>
diff --git a/tests/methods/bug622570.c-expected b/tests/methods/bug622570.c-expected
index 0787494f2f6d7c13..76ddce74c321ea7c 100644
--- a/tests/methods/bug622570.c-expected
+++ b/tests/methods/bug622570.c-expected
@@ -1,6 +1,13 @@
 /* methods_bug622570.c generated by valac, the Vala compiler
  * generated from methods_bug622570.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/methods/bug626783.c-expected b/tests/methods/bug626783.c-expected
index 4038dc962be18334..cda8b7cadbbf8cd0 100644
--- a/tests/methods/bug626783.c-expected
+++ b/tests/methods/bug626783.c-expected
@@ -1,6 +1,13 @@
 /* methods_bug626783.c generated by valac, the Vala compiler
  * generated from methods_bug626783.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
 #include <glib.h>
diff --git a/tests/methods/bug634753.c-expected b/tests/methods/bug634753.c-expected
index e6398fe2efa5f207..6f11739095d3f0bc 100644
--- a/tests/methods/bug634753.c-expected
+++ b/tests/methods/bug634753.c-expected
@@ -1,6 +1,13 @@
 /* methods_bug634753.c generated by valac, the Vala compiler
  * generated from methods_bug634753.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/methods/bug639054.c-expected b/tests/methods/bug639054.c-expected
index 4429c8ebb6612433..b6ff37a2569a4819 100644
--- a/tests/methods/bug639054.c-expected
+++ b/tests/methods/bug639054.c-expected
@@ -1,6 +1,13 @@
 /* methods_bug639054.c generated by valac, the Vala compiler
  * generated from methods_bug639054.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <gio/gio.h>
 #include <stdlib.h>
diff --git a/tests/methods/bug642350.c-expected b/tests/methods/bug642350.c-expected
index 1048cb4b23ce12c4..ae81f9e637dd790d 100644
--- a/tests/methods/bug642350.c-expected
+++ b/tests/methods/bug642350.c-expected
@@ -1,6 +1,13 @@
 /* methods_bug642350.c generated by valac, the Vala compiler
  * generated from methods_bug642350.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/methods/bug642885.c-expected b/tests/methods/bug642885.c-expected
index 6b093eb1d5c84641..a3f446277e33d526 100644
--- a/tests/methods/bug642885.c-expected
+++ b/tests/methods/bug642885.c-expected
@@ -1,6 +1,13 @@
 /* methods_bug642885.c generated by valac, the Vala compiler
  * generated from methods_bug642885.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <gio/gio.h>
 #include <glib-object.h>
 #include <glib.h>
diff --git a/tests/methods/bug642899.c-expected b/tests/methods/bug642899.c-expected
index e95bb0f14ab2300c..a78f33fd3c7d23f3 100644
--- a/tests/methods/bug642899.c-expected
+++ b/tests/methods/bug642899.c-expected
@@ -1,6 +1,13 @@
 /* methods_bug642899.c generated by valac, the Vala compiler
  * generated from methods_bug642899.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/methods/bug646345.c-expected b/tests/methods/bug646345.c-expected
index 4591c3e1278ceb4e..a209ee6fabbcf508 100644
--- a/tests/methods/bug646345.c-expected
+++ b/tests/methods/bug646345.c-expected
@@ -1,6 +1,13 @@
 /* methods_bug646345.c generated by valac, the Vala compiler
  * generated from methods_bug646345.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/methods/bug648320.c-expected b/tests/methods/bug648320.c-expected
index 4026eba9dd6b23e5..aa9cd3e06f58a343 100644
--- a/tests/methods/bug648320.c-expected
+++ b/tests/methods/bug648320.c-expected
@@ -1,6 +1,13 @@
 /* methods_bug648320.c generated by valac, the Vala compiler
  * generated from methods_bug648320.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/methods/bug649562.c-expected b/tests/methods/bug649562.c-expected
index ec1d60c13ca9036e..26fa49efc0afeda1 100644
--- a/tests/methods/bug649562.c-expected
+++ b/tests/methods/bug649562.c-expected
@@ -1,6 +1,13 @@
 /* methods_bug649562.c generated by valac, the Vala compiler
  * generated from methods_bug649562.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 static void _vala_main (void);
diff --git a/tests/methods/bug652098.c-expected b/tests/methods/bug652098.c-expected
index 871617da4c2ab288..18f537c2b60fc450 100644
--- a/tests/methods/bug652098.c-expected
+++ b/tests/methods/bug652098.c-expected
@@ -1,6 +1,13 @@
 /* methods_bug652098.c generated by valac, the Vala compiler
  * generated from methods_bug652098.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/methods/bug653391.c-expected b/tests/methods/bug653391.c-expected
index 1f9c89ea603c5346..37c852d5790d31c5 100644
--- a/tests/methods/bug653391.c-expected
+++ b/tests/methods/bug653391.c-expected
@@ -1,6 +1,13 @@
 /* methods_bug653391.c generated by valac, the Vala compiler
  * generated from methods_bug653391.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/methods/bug653908.c-expected b/tests/methods/bug653908.c-expected
index 891aacdc34088fb2..21d6849e22658c3c 100644
--- a/tests/methods/bug653908.c-expected
+++ b/tests/methods/bug653908.c-expected
@@ -1,6 +1,13 @@
 /* methods_bug653908.c generated by valac, the Vala compiler
  * generated from methods_bug653908.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <string.h>
 
diff --git a/tests/methods/bug663210.c-expected b/tests/methods/bug663210.c-expected
index d248a449f2d0c227..e6c8bcbe7a990329 100644
--- a/tests/methods/bug663210.c-expected
+++ b/tests/methods/bug663210.c-expected
@@ -1,6 +1,13 @@
 /* methods_bug663210.c generated by valac, the Vala compiler
  * generated from methods_bug663210.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/methods/bug699956.c-expected b/tests/methods/bug699956.c-expected
index b8b789c115ea32d9..e452bcf18bf817e9 100644
--- a/tests/methods/bug699956.c-expected
+++ b/tests/methods/bug699956.c-expected
@@ -1,6 +1,13 @@
 /* methods_bug699956.c generated by valac, the Vala compiler
  * generated from methods_bug699956.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
 #include <glib.h>
diff --git a/tests/methods/bug710862.c-expected b/tests/methods/bug710862.c-expected
index a5a54036b5f5adfb..9afa97223a678b42 100644
--- a/tests/methods/bug710862.c-expected
+++ b/tests/methods/bug710862.c-expected
@@ -1,6 +1,13 @@
 /* methods_bug710862.c generated by valac, the Vala compiler
  * generated from methods_bug710862.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/methods/bug723009.c-expected b/tests/methods/bug723009.c-expected
index f7376c656ea93bed..f63a55175efa33b7 100644
--- a/tests/methods/bug723009.c-expected
+++ b/tests/methods/bug723009.c-expected
@@ -1,6 +1,13 @@
 /* methods_bug723009.c generated by valac, the Vala compiler
  * generated from methods_bug723009.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/methods/bug723195.c-expected b/tests/methods/bug723195.c-expected
index 1178b69b7ec85df6..5f325a1868239084 100644
--- a/tests/methods/bug723195.c-expected
+++ b/tests/methods/bug723195.c-expected
@@ -1,6 +1,13 @@
 /* methods_bug723195.c generated by valac, the Vala compiler
  * generated from methods_bug723195.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/methods/bug726347.c-expected b/tests/methods/bug726347.c-expected
index 84681feb5569c05a..0b994ab6ceb4c710 100644
--- a/tests/methods/bug726347.c-expected
+++ b/tests/methods/bug726347.c-expected
@@ -1,6 +1,13 @@
 /* methods_bug726347.c generated by valac, the Vala compiler
  * generated from methods_bug726347.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdarg.h>
diff --git a/tests/methods/bug736235.c-expected b/tests/methods/bug736235.c-expected
index 5f65d8936a40ffd3..8aa01ee799f3c581 100644
--- a/tests/methods/bug736235.c-expected
+++ b/tests/methods/bug736235.c-expected
@@ -1,6 +1,13 @@
 /* methods_bug736235.c generated by valac, the Vala compiler
  * generated from methods_bug736235.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/methods/bug737222.c-expected b/tests/methods/bug737222.c-expected
index c79c0cd513098fc7..0501e1b36a29ecd2 100644
--- a/tests/methods/bug737222.c-expected
+++ b/tests/methods/bug737222.c-expected
@@ -1,6 +1,13 @@
 /* methods_bug737222.c generated by valac, the Vala compiler
  * generated from methods_bug737222.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/methods/bug743877.c-expected b/tests/methods/bug743877.c-expected
index b5e893902fcf78c6..67a684590ce990f6 100644
--- a/tests/methods/bug743877.c-expected
+++ b/tests/methods/bug743877.c-expected
@@ -1,6 +1,13 @@
 /* methods_bug743877.c generated by valac, the Vala compiler
  * generated from methods_bug743877.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <locale.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/methods/bug771964.c-expected b/tests/methods/bug771964.c-expected
index 74f16bb9afa55609..4f84e825e2b6b4d5 100644
--- a/tests/methods/bug771964.c-expected
+++ b/tests/methods/bug771964.c-expected
@@ -1,6 +1,13 @@
 /* methods_bug771964.c generated by valac, the Vala compiler
  * generated from methods_bug771964.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdio.h>
diff --git a/tests/methods/bug774060.c-expected b/tests/methods/bug774060.c-expected
index 367b76b790afdde1..e33e228d21e10a91 100644
--- a/tests/methods/bug774060.c-expected
+++ b/tests/methods/bug774060.c-expected
@@ -1,6 +1,13 @@
 /* methods_bug774060.c generated by valac, the Vala compiler
  * generated from methods_bug774060.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/methods/bug781061.c-expected b/tests/methods/bug781061.c-expected
index 477b8e67fe33ed90..d5e2ba2eaa220d63 100644
--- a/tests/methods/bug781061.c-expected
+++ b/tests/methods/bug781061.c-expected
@@ -1,6 +1,13 @@
 /* methods_bug781061.c generated by valac, the Vala compiler
  * generated from methods_bug781061.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <stdlib.h>
diff --git a/tests/methods/bug784691.c-expected b/tests/methods/bug784691.c-expected
index 7c7ccccecf517217..e8adbdc040317b77 100644
--- a/tests/methods/bug784691.c-expected
+++ b/tests/methods/bug784691.c-expected
@@ -1,6 +1,13 @@
 /* methods_bug784691.c generated by valac, the Vala compiler
  * generated from methods_bug784691.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/methods/bug791215.c-expected b/tests/methods/bug791215.c-expected
index 69066096a03d94b0..4eca691b2ed532d5 100644
--- a/tests/methods/bug791215.c-expected
+++ b/tests/methods/bug791215.c-expected
@@ -1,6 +1,13 @@
 /* methods_bug791215.c generated by valac, the Vala compiler
  * generated from methods_bug791215.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/methods/bug791283.c-expected b/tests/methods/bug791283.c-expected
index 30d862fdf37b90bc..ad4249399f4aad10 100644
--- a/tests/methods/bug791283.c-expected
+++ b/tests/methods/bug791283.c-expected
@@ -1,6 +1,13 @@
 /* methods_bug791283.c generated by valac, the Vala compiler
  * generated from methods_bug791283.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/methods/closures.c-expected b/tests/methods/closures.c-expected
index baafa40d99bbe743..eb5c32522c14ac48 100644
--- a/tests/methods/closures.c-expected
+++ b/tests/methods/closures.c-expected
@@ -1,6 +1,13 @@
 /* methods_closures.c generated by valac, the Vala compiler
  * generated from methods_closures.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/methods/contains.c-expected b/tests/methods/contains.c-expected
index 38ce0855dcb643e5..44f66cdd7605018a 100644
--- a/tests/methods/contains.c-expected
+++ b/tests/methods/contains.c-expected
@@ -1,6 +1,13 @@
 /* methods_contains.c generated by valac, the Vala compiler
  * generated from methods_contains.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/methods/delegate-target.c-expected b/tests/methods/delegate-target.c-expected
index f1c6add6cdd52e5b..460e2dcd56564fb6 100644
--- a/tests/methods/delegate-target.c-expected
+++ b/tests/methods/delegate-target.c-expected
@@ -1,6 +1,13 @@
 /* methods_delegate_target.c generated by valac, the Vala compiler
  * generated from methods_delegate_target.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/methods/extern.c-expected b/tests/methods/extern.c-expected
index e8877a601b18317a..a8843c8af5e8171e 100644
--- a/tests/methods/extern.c-expected
+++ b/tests/methods/extern.c-expected
@@ -1,6 +1,13 @@
 /* methods_extern.c generated by valac, the Vala compiler
  * generated from methods_extern.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/methods/generics.c-expected b/tests/methods/generics.c-expected
index 8cc76765bd0d7988..8c85c8389a8b531e 100644
--- a/tests/methods/generics.c-expected
+++ b/tests/methods/generics.c-expected
@@ -1,6 +1,13 @@
 /* methods_generics.c generated by valac, the Vala compiler
  * generated from methods_generics.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/methods/iterator.c-expected b/tests/methods/iterator.c-expected
index 9f20bc38acb484d4..579a39a6fd8b71ec 100644
--- a/tests/methods/iterator.c-expected
+++ b/tests/methods/iterator.c-expected
@@ -1,6 +1,13 @@
 /* methods_iterator.c generated by valac, the Vala compiler
  * generated from methods_iterator.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
 #include <glib.h>
diff --git a/tests/methods/lambda.c-expected b/tests/methods/lambda.c-expected
index 2eaa626423a26504..427d57bf3e96bcab 100644
--- a/tests/methods/lambda.c-expected
+++ b/tests/methods/lambda.c-expected
@@ -1,6 +1,13 @@
 /* methods_lambda.c generated by valac, the Vala compiler
  * generated from methods_lambda.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/methods/local-functions.c-expected b/tests/methods/local-functions.c-expected
index 92ac20ce4b1bdb2f..164f15db60aa22ae 100644
--- a/tests/methods/local-functions.c-expected
+++ b/tests/methods/local-functions.c-expected
@@ -1,6 +1,13 @@
 /* methods_local_functions.c generated by valac, the Vala compiler
  * generated from methods_local_functions.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/methods/nowrapper-interface.c-expected b/tests/methods/nowrapper-interface.c-expected
index 92cf1c1e7b12beac..231426442575d08d 100644
--- a/tests/methods/nowrapper-interface.c-expected
+++ b/tests/methods/nowrapper-interface.c-expected
@@ -1,6 +1,13 @@
 /* methods_nowrapper_interface.c generated by valac, the Vala compiler
  * generated from methods_nowrapper_interface.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/methods/parameter-ccode-type.c-expected b/tests/methods/parameter-ccode-type.c-expected
index 1718ba5dcb423bf4..7726ca7643511f70 100644
--- a/tests/methods/parameter-ccode-type.c-expected
+++ b/tests/methods/parameter-ccode-type.c-expected
@@ -1,6 +1,13 @@
 /* methods_parameter_ccode_type.c generated by valac, the Vala compiler
  * generated from methods_parameter_ccode_type.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/methods/parameter-fixed-array-initializer.c-expected b/tests/methods/parameter-fixed-array-initializer.c-expected
index b940fab63abadb53..9d3baf319be6a429 100644
--- a/tests/methods/parameter-fixed-array-initializer.c-expected
+++ b/tests/methods/parameter-fixed-array-initializer.c-expected
@@ -1,6 +1,13 @@
 /* methods_parameter_fixed_array_initializer.c generated by valac, the Vala compiler
  * generated from methods_parameter_fixed_array_initializer.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <float.h>
diff --git a/tests/methods/parameter-out-free-on-error.c-expected b/tests/methods/parameter-out-free-on-error.c-expected
index 1cd0a5cbe62d8c8a..36e9050c870c9005 100644
--- a/tests/methods/parameter-out-free-on-error.c-expected
+++ b/tests/methods/parameter-out-free-on-error.c-expected
@@ -1,6 +1,13 @@
 /* methods_parameter_out_free_on_error.c generated by valac, the Vala compiler
  * generated from methods_parameter_out_free_on_error.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/methods/parameter-ref-array-resize-captured.c-expected b/tests/methods/parameter-ref-array-resize-captured.c-expected
index 2b06a3a23e6dc287..91fe4d674eb7fba8 100644
--- a/tests/methods/parameter-ref-array-resize-captured.c-expected
+++ b/tests/methods/parameter-ref-array-resize-captured.c-expected
@@ -1,6 +1,13 @@
 /* methods_parameter_ref_array_resize_captured.c generated by valac, the Vala compiler
  * generated from methods_parameter_ref_array_resize_captured.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/methods/parameter-ref-array-resize.c-expected b/tests/methods/parameter-ref-array-resize.c-expected
index ece83e9884d207d7..46f837c6e5f66a08 100644
--- a/tests/methods/parameter-ref-array-resize.c-expected
+++ b/tests/methods/parameter-ref-array-resize.c-expected
@@ -1,6 +1,13 @@
 /* methods_parameter_ref_array_resize.c generated by valac, the Vala compiler
  * generated from methods_parameter_ref_array_resize.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/methods/parameter-ref-delegate.c-expected b/tests/methods/parameter-ref-delegate.c-expected
index dafddddf65956a96..c79c947320e9a3c4 100644
--- a/tests/methods/parameter-ref-delegate.c-expected
+++ b/tests/methods/parameter-ref-delegate.c-expected
@@ -1,6 +1,13 @@
 /* methods_parameter_ref_delegate.c generated by valac, the Vala compiler
  * generated from methods_parameter_ref_delegate.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/methods/parameter-ref-element-access.c-expected b/tests/methods/parameter-ref-element-access.c-expected
index e87761df92ac8f7e..440ce3f66676a922 100644
--- a/tests/methods/parameter-ref-element-access.c-expected
+++ b/tests/methods/parameter-ref-element-access.c-expected
@@ -1,6 +1,13 @@
 /* methods_parameter_ref_element_access.c generated by valac, the Vala compiler
  * generated from methods_parameter_ref_element_access.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/methods/params-array-with-throws.c-expected b/tests/methods/params-array-with-throws.c-expected
index 43e3f55d65a59df1..1c602f8bf1a12b80 100644
--- a/tests/methods/params-array-with-throws.c-expected
+++ b/tests/methods/params-array-with-throws.c-expected
@@ -1,6 +1,13 @@
 /* methods_params_array_with_throws.c generated by valac, the Vala compiler
  * generated from methods_params_array_with_throws.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <stdlib.h>
diff --git a/tests/methods/params-array.c-expected b/tests/methods/params-array.c-expected
index 00cd25a25166d635..e18a77c93dd31617 100644
--- a/tests/methods/params-array.c-expected
+++ b/tests/methods/params-array.c-expected
@@ -1,6 +1,13 @@
 /* methods_params_array.c generated by valac, the Vala compiler
  * generated from methods_params_array.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/methods/postconditions-temp-variables.c-expected b/tests/methods/postconditions-temp-variables.c-expected
index fbc76445f7de4100..e66c1a00307f4d12 100644
--- a/tests/methods/postconditions-temp-variables.c-expected
+++ b/tests/methods/postconditions-temp-variables.c-expected
@@ -1,6 +1,13 @@
 /* methods_postconditions_temp_variables.c generated by valac, the Vala compiler
  * generated from methods_postconditions_temp_variables.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/methods/postconditions.c-expected b/tests/methods/postconditions.c-expected
index f577e535d07cbfbc..e2707489fddc26f4 100644
--- a/tests/methods/postconditions.c-expected
+++ b/tests/methods/postconditions.c-expected
@@ -1,6 +1,13 @@
 /* methods_postconditions.c generated by valac, the Vala compiler
  * generated from methods_postconditions.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/methods/preconditions-temp-variables.c-expected b/tests/methods/preconditions-temp-variables.c-expected
index 25d4267b344b435c..a91bbe012587d9db 100644
--- a/tests/methods/preconditions-temp-variables.c-expected
+++ b/tests/methods/preconditions-temp-variables.c-expected
@@ -1,6 +1,13 @@
 /* methods_preconditions_temp_variables.c generated by valac, the Vala compiler
  * generated from methods_preconditions_temp_variables.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/methods/prepostconditions-captured.c-expected b/tests/methods/prepostconditions-captured.c-expected
index 7d8484f552ce8aa6..4e3088d200935078 100644
--- a/tests/methods/prepostconditions-captured.c-expected
+++ b/tests/methods/prepostconditions-captured.c-expected
@@ -1,6 +1,13 @@
 /* methods_prepostconditions_captured.c generated by valac, the Vala compiler
  * generated from methods_prepostconditions_captured.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <gio/gio.h>
 
diff --git a/tests/methods/prepostconditions-contains.c-expected b/tests/methods/prepostconditions-contains.c-expected
index 5409cd2186b16d19..86353d0d05767907 100644
--- a/tests/methods/prepostconditions-contains.c-expected
+++ b/tests/methods/prepostconditions-contains.c-expected
@@ -1,6 +1,13 @@
 /* methods_prepostconditions_contains.c generated by valac, the Vala compiler
  * generated from methods_prepostconditions_contains.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/methods/prepostconditions.c-expected b/tests/methods/prepostconditions.c-expected
index b9917451637d450c..ddebdbeab5c69ca7 100644
--- a/tests/methods/prepostconditions.c-expected
+++ b/tests/methods/prepostconditions.c-expected
@@ -1,6 +1,13 @@
 /* methods_prepostconditions.c generated by valac, the Vala compiler
  * generated from methods_prepostconditions.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/methods/print-attribute.c-expected b/tests/methods/print-attribute.c-expected
index 744d84bb9c8f0b33..9801e38f03e3681f 100644
--- a/tests/methods/print-attribute.c-expected
+++ b/tests/methods/print-attribute.c-expected
@@ -1,6 +1,13 @@
 /* methods_print_attribute.c generated by valac, the Vala compiler
  * generated from methods_print_attribute.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <stdlib.h>
diff --git a/tests/methods/printf-constructor.c-expected b/tests/methods/printf-constructor.c-expected
index 6f465f49568efdcc..9546af1494003be1 100644
--- a/tests/methods/printf-constructor.c-expected
+++ b/tests/methods/printf-constructor.c-expected
@@ -1,6 +1,13 @@
 /* methods_printf_constructor.c generated by valac, the Vala compiler
  * generated from methods_printf_constructor.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #define _g_error_free0(var) ((var == NULL) ? NULL : (var = (g_error_free (var), NULL)))
diff --git a/tests/methods/profile.c-expected b/tests/methods/profile.c-expected
index 9a0bba52beccb78e..a802ab7352940d5b 100644
--- a/tests/methods/profile.c-expected
+++ b/tests/methods/profile.c-expected
@@ -1,6 +1,13 @@
 /* methods_profile.c generated by valac, the Vala compiler
  * generated from methods_profile.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdio.h>
 #include <glib.h>
 
diff --git a/tests/methods/return-unowned-delegate.c-expected b/tests/methods/return-unowned-delegate.c-expected
index 96904ba1e560467e..586193e2e10f55f8 100644
--- a/tests/methods/return-unowned-delegate.c-expected
+++ b/tests/methods/return-unowned-delegate.c-expected
@@ -1,6 +1,13 @@
 /* methods_return_unowned_delegate.c generated by valac, the Vala compiler
  * generated from methods_return_unowned_delegate.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/methods/same-name.c-expected b/tests/methods/same-name.c-expected
index e68b4f3d21f70646..a2aee0a899322305 100644
--- a/tests/methods/same-name.c-expected
+++ b/tests/methods/same-name.c-expected
@@ -1,6 +1,13 @@
 /* methods_same_name.c generated by valac, the Vala compiler
  * generated from methods_same_name.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/methods/symbolresolution.c-expected b/tests/methods/symbolresolution.c-expected
index 301a18c58c5f4d8f..d6e32eb2fb0f4809 100644
--- a/tests/methods/symbolresolution.c-expected
+++ b/tests/methods/symbolresolution.c-expected
@@ -1,6 +1,13 @@
 /* methods_symbolresolution.c generated by valac, the Vala compiler
  * generated from methods_symbolresolution.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/methods/varargs-delegate-without-target.c-expected b/tests/methods/varargs-delegate-without-target.c-expected
index 5b8caa4811a3c1ae..0d949b4042955795 100644
--- a/tests/methods/varargs-delegate-without-target.c-expected
+++ b/tests/methods/varargs-delegate-without-target.c-expected
@@ -1,6 +1,13 @@
 /* methods_varargs_delegate_without_target.c generated by valac, the Vala compiler
  * generated from methods_varargs_delegate_without_target.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/methods/varargs-delegate.c-expected b/tests/methods/varargs-delegate.c-expected
index 2a20d4e156a00f1e..a047f8933fc3b458 100644
--- a/tests/methods/varargs-delegate.c-expected
+++ b/tests/methods/varargs-delegate.c-expected
@@ -1,6 +1,13 @@
 /* methods_varargs_delegate.c generated by valac, the Vala compiler
  * generated from methods_varargs_delegate.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/methods/varargs-gvalue.c-expected b/tests/methods/varargs-gvalue.c-expected
index 5c5d26a69220be5c..949df24aef79e33e 100644
--- a/tests/methods/varargs-gvalue.c-expected
+++ b/tests/methods/varargs-gvalue.c-expected
@@ -1,6 +1,13 @@
 /* methods_varargs_gvalue.c generated by valac, the Vala compiler
  * generated from methods_varargs_gvalue.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <stdarg.h>
 #include <glib-object.h>
diff --git a/tests/methods/varargs-out.c-expected b/tests/methods/varargs-out.c-expected
index 35e5ef5eb6d09fca..a75273bb2cf6b289 100644
--- a/tests/methods/varargs-out.c-expected
+++ b/tests/methods/varargs-out.c-expected
@@ -1,6 +1,13 @@
 /* methods_varargs_out.c generated by valac, the Vala compiler
  * generated from methods_varargs_out.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/methods/varargs-ref.c-expected b/tests/methods/varargs-ref.c-expected
index cc68f4ab71d7a5b2..4d33059bbe540f1e 100644
--- a/tests/methods/varargs-ref.c-expected
+++ b/tests/methods/varargs-ref.c-expected
@@ -1,6 +1,13 @@
 /* methods_varargs_ref.c generated by valac, the Vala compiler
  * generated from methods_varargs_ref.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/methods/varargs-struct.c-expected b/tests/methods/varargs-struct.c-expected
index 5b6e85af94a524f7..eb337d91d20637ec 100644
--- a/tests/methods/varargs-struct.c-expected
+++ b/tests/methods/varargs-struct.c-expected
@@ -1,6 +1,13 @@
 /* methods_varargs_struct.c generated by valac, the Vala compiler
  * generated from methods_varargs_struct.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <string.h>
 #include <stdarg.h>
diff --git a/tests/namespace/unique.c-expected b/tests/namespace/unique.c-expected
index 102796fd020fa91a..c86733f455d5b4b3 100644
--- a/tests/namespace/unique.c-expected
+++ b/tests/namespace/unique.c-expected
@@ -1,6 +1,13 @@
 /* namespace_unique.c generated by valac, the Vala compiler
  * generated from namespace_unique.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
 #include <glib.h>
diff --git a/tests/nullability/array-element-class.c-expected b/tests/nullability/array-element-class.c-expected
index db59e2382770ec29..089b4da590ddb8c8 100644
--- a/tests/nullability/array-element-class.c-expected
+++ b/tests/nullability/array-element-class.c-expected
@@ -1,6 +1,13 @@
 /* nullability_array_element_class.c generated by valac, the Vala compiler
  * generated from nullability_array_element_class.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
 #include <glib.h>
diff --git a/tests/nullability/array-element-string.c-expected b/tests/nullability/array-element-string.c-expected
index 4ce699022505d869..182e2b0a314de2e3 100644
--- a/tests/nullability/array-element-string.c-expected
+++ b/tests/nullability/array-element-string.c-expected
@@ -1,6 +1,13 @@
 /* nullability_array_element_string.c generated by valac, the Vala compiler
  * generated from nullability_array_element_string.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/nullability/bug611223.c-expected b/tests/nullability/bug611223.c-expected
index e79eb96908bfc4bf..3380cba0f4e5a587 100644
--- a/tests/nullability/bug611223.c-expected
+++ b/tests/nullability/bug611223.c-expected
@@ -1,6 +1,13 @@
 /* nullability_bug611223.c generated by valac, the Vala compiler
  * generated from nullability_bug611223.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/nullability/member-access-narrowed-instance.c-expected b/tests/nullability/member-access-narrowed-instance.c-expected
index 4f4051bc1f366e69..052a753c65cd4ab3 100644
--- a/tests/nullability/member-access-narrowed-instance.c-expected
+++ b/tests/nullability/member-access-narrowed-instance.c-expected
@@ -1,6 +1,13 @@
 /* nullability_member_access_narrowed_instance.c generated by valac, the Vala compiler
  * generated from nullability_member_access_narrowed_instance.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/nullability/var-type.c-expected b/tests/nullability/var-type.c-expected
index 10be13b515f09979..6f909b53ce8b6223 100644
--- a/tests/nullability/var-type.c-expected
+++ b/tests/nullability/var-type.c-expected
@@ -1,6 +1,13 @@
 /* nullability_var_type.c generated by valac, the Vala compiler
  * generated from nullability_var_type.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/objects/bug566909.c-expected b/tests/objects/bug566909.c-expected
index 05ada381fd9eee19..93020af9d1155b86 100644
--- a/tests/objects/bug566909.c-expected
+++ b/tests/objects/bug566909.c-expected
@@ -1,6 +1,13 @@
 /* objects_bug566909.c generated by valac, the Vala compiler
  * generated from objects_bug566909.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/objects/bug588203.c-expected b/tests/objects/bug588203.c-expected
index 762390cd123c9f0d..85851f38e6f00a28 100644
--- a/tests/objects/bug588203.c-expected
+++ b/tests/objects/bug588203.c-expected
@@ -1,6 +1,13 @@
 /* objects_bug588203.c generated by valac, the Vala compiler
  * generated from objects_bug588203.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/bug589928.c-expected b/tests/objects/bug589928.c-expected
index 9dcde3e70851b919..3588b48019af7ae8 100644
--- a/tests/objects/bug589928.c-expected
+++ b/tests/objects/bug589928.c-expected
@@ -1,6 +1,13 @@
 /* objects_bug589928.c generated by valac, the Vala compiler
  * generated from objects_bug589928.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/objects/bug593137.c-expected b/tests/objects/bug593137.c-expected
index 287bc43fa899232f..37bc0f1c251282eb 100644
--- a/tests/objects/bug593137.c-expected
+++ b/tests/objects/bug593137.c-expected
@@ -1,6 +1,13 @@
 /* objects_bug593137.c generated by valac, the Vala compiler
  * generated from objects_bug593137.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/objects/bug593260.c-expected b/tests/objects/bug593260.c-expected
index a0b3fb9c8b5d49be..c7039097506deb1f 100644
--- a/tests/objects/bug593260.c-expected
+++ b/tests/objects/bug593260.c-expected
@@ -1,6 +1,13 @@
 /* objects_bug593260.c generated by valac, the Vala compiler
  * generated from objects_bug593260.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/bug596621.c-expected b/tests/objects/bug596621.c-expected
index 1beebed6c67d1b40..d17d5e8594e36bde 100644
--- a/tests/objects/bug596621.c-expected
+++ b/tests/objects/bug596621.c-expected
@@ -1,6 +1,13 @@
 /* objects_bug596621.c generated by valac, the Vala compiler
  * generated from objects_bug596621.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/objects/bug597155.c-expected b/tests/objects/bug597155.c-expected
index e1336728c9141e46..7f71f9f9d60c1925 100644
--- a/tests/objects/bug597155.c-expected
+++ b/tests/objects/bug597155.c-expected
@@ -1,6 +1,13 @@
 /* objects_bug597155.c generated by valac, the Vala compiler
  * generated from objects_bug597155.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/objects/bug597161.c-expected b/tests/objects/bug597161.c-expected
index 958cbda3e73cab35..b766a91f90e9b40f 100644
--- a/tests/objects/bug597161.c-expected
+++ b/tests/objects/bug597161.c-expected
@@ -1,6 +1,13 @@
 /* objects_bug597161.c generated by valac, the Vala compiler
  * generated from objects_bug597161.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/objects/bug613486.c-expected b/tests/objects/bug613486.c-expected
index ce02c4d4a18526d2..9f6cf1e1361b0bed 100644
--- a/tests/objects/bug613486.c-expected
+++ b/tests/objects/bug613486.c-expected
@@ -1,6 +1,13 @@
 /* objects_bug613486.c generated by valac, the Vala compiler
  * generated from objects_bug613486.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/bug613840.c-expected b/tests/objects/bug613840.c-expected
index 3acd5e764c1735a7..85b7e60de6e691b1 100644
--- a/tests/objects/bug613840.c-expected
+++ b/tests/objects/bug613840.c-expected
@@ -1,6 +1,13 @@
 /* objects_bug613840.c generated by valac, the Vala compiler
  * generated from objects_bug613840.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/objects/bug620675.c-expected b/tests/objects/bug620675.c-expected
index 46dd1a3a0db1a346..cf974333ae6ecf8f 100644
--- a/tests/objects/bug620675.c-expected
+++ b/tests/objects/bug620675.c-expected
@@ -1,6 +1,13 @@
 /* objects_bug620675.c generated by valac, the Vala compiler
  * generated from objects_bug620675.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/objects/bug620706.c-expected b/tests/objects/bug620706.c-expected
index 7165a7b62cbd69ba..1d34d0ee37fe8b51 100644
--- a/tests/objects/bug620706.c-expected
+++ b/tests/objects/bug620706.c-expected
@@ -1,6 +1,13 @@
 /* objects_bug620706.c generated by valac, the Vala compiler
  * generated from objects_bug620706.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/objects/bug624594.c-expected b/tests/objects/bug624594.c-expected
index ee199a553cff417e..ca64d82730190100 100644
--- a/tests/objects/bug624594.c-expected
+++ b/tests/objects/bug624594.c-expected
@@ -1,6 +1,13 @@
 /* objects_bug624594.c generated by valac, the Vala compiler
  * generated from objects_bug624594.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/objects/bug626038-2.c-expected b/tests/objects/bug626038-2.c-expected
index 9c4f767bf23f0165..6128f82ef4a0f338 100644
--- a/tests/objects/bug626038-2.c-expected
+++ b/tests/objects/bug626038-2.c-expected
@@ -1,6 +1,13 @@
 /* objects_bug626038_2.c generated by valac, the Vala compiler
  * generated from objects_bug626038_2.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
 #include <glib.h>
diff --git a/tests/objects/bug626038.c-expected b/tests/objects/bug626038.c-expected
index 994cb86ac6577ded..82fea932978318f3 100644
--- a/tests/objects/bug626038.c-expected
+++ b/tests/objects/bug626038.c-expected
@@ -1,6 +1,13 @@
 /* objects_bug626038.c generated by valac, the Vala compiler
  * generated from objects_bug626038.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
 
diff --git a/tests/objects/bug628639.c-expected b/tests/objects/bug628639.c-expected
index 71864fa2e047b1ac..0277dbe7dc21fdcc 100644
--- a/tests/objects/bug628639.c-expected
+++ b/tests/objects/bug628639.c-expected
@@ -1,6 +1,13 @@
 /* objects_bug628639.c generated by valac, the Vala compiler
  * generated from objects_bug628639.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/bug629593.c-expected b/tests/objects/bug629593.c-expected
index 4f4814f0190849cd..7a6ad6a7a1154912 100644
--- a/tests/objects/bug629593.c-expected
+++ b/tests/objects/bug629593.c-expected
@@ -1,6 +1,13 @@
 /* objects_bug629593.c generated by valac, the Vala compiler
  * generated from objects_bug629593.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/bug631267.c-expected b/tests/objects/bug631267.c-expected
index 7f39c30d055fb512..33c3f0fc29f0286b 100644
--- a/tests/objects/bug631267.c-expected
+++ b/tests/objects/bug631267.c-expected
@@ -1,6 +1,13 @@
 /* objects_bug631267.c generated by valac, the Vala compiler
  * generated from objects_bug631267.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/objects/bug634782.c-expected b/tests/objects/bug634782.c-expected
index 9aaf333e7d2413d4..ecababe991d14fe2 100644
--- a/tests/objects/bug634782.c-expected
+++ b/tests/objects/bug634782.c-expected
@@ -1,6 +1,13 @@
 /* objects_bug634782.c generated by valac, the Vala compiler
  * generated from objects_bug634782.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/bug641828.c-expected b/tests/objects/bug641828.c-expected
index 9ce869b9c19228fb..aaca52992bcc45b4 100644
--- a/tests/objects/bug641828.c-expected
+++ b/tests/objects/bug641828.c-expected
@@ -1,6 +1,13 @@
 /* objects_bug641828.c generated by valac, the Vala compiler
  * generated from objects_bug641828.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/objects/bug642809.c-expected b/tests/objects/bug642809.c-expected
index 01a87924443a3a6d..99f07ae887a5d3cb 100644
--- a/tests/objects/bug642809.c-expected
+++ b/tests/objects/bug642809.c-expected
@@ -1,6 +1,13 @@
 /* objects_bug642809.c generated by valac, the Vala compiler
  * generated from objects_bug642809.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/objects/bug643711.c-expected b/tests/objects/bug643711.c-expected
index c6f609155f69ffab..157ac837aa585514 100644
--- a/tests/objects/bug643711.c-expected
+++ b/tests/objects/bug643711.c-expected
@@ -1,6 +1,13 @@
 /* objects_bug643711.c generated by valac, the Vala compiler
  * generated from objects_bug643711.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/objects/bug644938.c-expected b/tests/objects/bug644938.c-expected
index cc264a45b2ebf866..6ff12b258f8f5128 100644
--- a/tests/objects/bug644938.c-expected
+++ b/tests/objects/bug644938.c-expected
@@ -1,6 +1,13 @@
 /* objects_bug644938.c generated by valac, the Vala compiler
  * generated from objects_bug644938.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/objects/bug646362.c-expected b/tests/objects/bug646362.c-expected
index ebe50de6b9e27c3b..315134a3665b270b 100644
--- a/tests/objects/bug646362.c-expected
+++ b/tests/objects/bug646362.c-expected
@@ -1,6 +1,13 @@
 /* objects_bug646362.c generated by valac, the Vala compiler
  * generated from objects_bug646362.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/objects/bug646792.c-expected b/tests/objects/bug646792.c-expected
index a2d9bfcec9e941b0..84ed47f2a54d1460 100644
--- a/tests/objects/bug646792.c-expected
+++ b/tests/objects/bug646792.c-expected
@@ -1,6 +1,13 @@
 /* objects_bug646792.c generated by valac, the Vala compiler
  * generated from objects_bug646792.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
 #include <stdlib.h>
diff --git a/tests/objects/bug647018.c-expected b/tests/objects/bug647018.c-expected
index 5ddb3f2167f8510d..a106ad3242e031f9 100644
--- a/tests/objects/bug647018.c-expected
+++ b/tests/objects/bug647018.c-expected
@@ -2,6 +2,12 @@
  * generated from objects_bug647018.vala, do not modify */
 
 /* allow fields starting with a digit if the cname is valid*/
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
 
 #include <glib.h>
 
diff --git a/tests/objects/bug653138.c-expected b/tests/objects/bug653138.c-expected
index eaef9d195c42e825..8a87e5c9f2446d8a 100644
--- a/tests/objects/bug653138.c-expected
+++ b/tests/objects/bug653138.c-expected
@@ -1,6 +1,13 @@
 /* objects_bug653138.c generated by valac, the Vala compiler
  * generated from objects_bug653138.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/bug654702.c-expected b/tests/objects/bug654702.c-expected
index 0d0b8a4302118cfe..804761db303567ec 100644
--- a/tests/objects/bug654702.c-expected
+++ b/tests/objects/bug654702.c-expected
@@ -1,6 +1,13 @@
 /* objects_bug654702.c generated by valac, the Vala compiler
  * generated from objects_bug654702.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/bug663134.c-expected b/tests/objects/bug663134.c-expected
index 945de99f5ee7ab82..12e14b3e0439146c 100644
--- a/tests/objects/bug663134.c-expected
+++ b/tests/objects/bug663134.c-expected
@@ -1,6 +1,13 @@
 /* objects_bug663134.c generated by valac, the Vala compiler
  * generated from objects_bug663134.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/bug664529.c-expected b/tests/objects/bug664529.c-expected
index 42398dc81d79b6d7..2853783a845971dc 100644
--- a/tests/objects/bug664529.c-expected
+++ b/tests/objects/bug664529.c-expected
@@ -1,6 +1,13 @@
 /* objects_bug664529.c generated by valac, the Vala compiler
  * generated from objects_bug664529.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/objects/bug681356.c-expected b/tests/objects/bug681356.c-expected
index 82fff780e4f4971a..d2dd9dac28cc5ed2 100644
--- a/tests/objects/bug681356.c-expected
+++ b/tests/objects/bug681356.c-expected
@@ -1,6 +1,13 @@
 /* objects_bug681356.c generated by valac, the Vala compiler
  * generated from objects_bug681356.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/objects/bug683646.c-expected b/tests/objects/bug683646.c-expected
index 97f2b21a25127a31..6e596d55e5761f83 100644
--- a/tests/objects/bug683646.c-expected
+++ b/tests/objects/bug683646.c-expected
@@ -1,6 +1,13 @@
 /* objects_bug683646.c generated by valac, the Vala compiler
  * generated from objects_bug683646.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/objects/bug695671.c-expected b/tests/objects/bug695671.c-expected
index bd8cf12956cf19a9..e993da4821df8769 100644
--- a/tests/objects/bug695671.c-expected
+++ b/tests/objects/bug695671.c-expected
@@ -1,6 +1,13 @@
 /* objects_bug695671.c generated by valac, the Vala compiler
  * generated from objects_bug695671.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/objects/bug702736.c-expected b/tests/objects/bug702736.c-expected
index 49621ee3c3889112..79f53cde0ec87d8c 100644
--- a/tests/objects/bug702736.c-expected
+++ b/tests/objects/bug702736.c-expected
@@ -1,6 +1,13 @@
 /* objects_bug702736.c generated by valac, the Vala compiler
  * generated from objects_bug702736.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/objects/bug702846.c-expected b/tests/objects/bug702846.c-expected
index 452e33ef12febe22..394e1543ff9eeee6 100644
--- a/tests/objects/bug702846.c-expected
+++ b/tests/objects/bug702846.c-expected
@@ -1,6 +1,13 @@
 /* objects_bug702846.c generated by valac, the Vala compiler
  * generated from objects_bug702846.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/bug731547.c-expected b/tests/objects/bug731547.c-expected
index 51d6391aa4ef705c..1bfa175e5825d6b2 100644
--- a/tests/objects/bug731547.c-expected
+++ b/tests/objects/bug731547.c-expected
@@ -1,6 +1,13 @@
 /* objects_bug731547.c generated by valac, the Vala compiler
  * generated from objects_bug731547.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/objects/bug741465.c-expected b/tests/objects/bug741465.c-expected
index d52a7a5604d22128..6114ba62182b0992 100644
--- a/tests/objects/bug741465.c-expected
+++ b/tests/objects/bug741465.c-expected
@@ -1,6 +1,13 @@
 /* objects_bug741465.c generated by valac, the Vala compiler
  * generated from objects_bug741465.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/objects/bug751338.c-expected b/tests/objects/bug751338.c-expected
index b03bc708b608e36e..c19132fe39b49b91 100644
--- a/tests/objects/bug751338.c-expected
+++ b/tests/objects/bug751338.c-expected
@@ -1,6 +1,13 @@
 /* objects_bug751338.c generated by valac, the Vala compiler
  * generated from objects_bug751338.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/bug758816.c-expected b/tests/objects/bug758816.c-expected
index c22e446368351091..4831b0f68cee8b90 100644
--- a/tests/objects/bug758816.c-expected
+++ b/tests/objects/bug758816.c-expected
@@ -1,6 +1,13 @@
 /* objects_bug758816.c generated by valac, the Vala compiler
  * generated from objects_bug758816.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/objects/bug764481.c-expected b/tests/objects/bug764481.c-expected
index b9404cec098ec7d0..19e99afb95c30c0e 100644
--- a/tests/objects/bug764481.c-expected
+++ b/tests/objects/bug764481.c-expected
@@ -1,6 +1,13 @@
 /* objects_bug764481.c generated by valac, the Vala compiler
  * generated from objects_bug764481.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/objects/bug766739.c-expected b/tests/objects/bug766739.c-expected
index 17f4adb529afc5eb..9026dd7cbc6de3e5 100644
--- a/tests/objects/bug766739.c-expected
+++ b/tests/objects/bug766739.c-expected
@@ -1,6 +1,13 @@
 /* objects_bug766739.c generated by valac, the Vala compiler
  * generated from objects_bug766739.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/objects/bug778632.c-expected b/tests/objects/bug778632.c-expected
index ef8387d12cbf8b8a..336b26b112ff9889 100644
--- a/tests/objects/bug778632.c-expected
+++ b/tests/objects/bug778632.c-expected
@@ -1,6 +1,13 @@
 /* objects_bug778632.c generated by valac, the Vala compiler
  * generated from objects_bug778632.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/objects/bug779219.c-expected b/tests/objects/bug779219.c-expected
index d2eb9960943abc62..7cee730cb03693f2 100644
--- a/tests/objects/bug779219.c-expected
+++ b/tests/objects/bug779219.c-expected
@@ -1,6 +1,13 @@
 /* objects_bug779219.c generated by valac, the Vala compiler
  * generated from objects_bug779219.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/objects/bug779955.c-expected b/tests/objects/bug779955.c-expected
index 43451cbc91a5b3af..6a631c8abe6c2d41 100644
--- a/tests/objects/bug779955.c-expected
+++ b/tests/objects/bug779955.c-expected
@@ -1,6 +1,13 @@
 /* objects_bug779955.c generated by valac, the Vala compiler
  * generated from objects_bug779955.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/objects/bug783897.c-expected b/tests/objects/bug783897.c-expected
index 389f3a547d282dc4..45d6b406ab235717 100644
--- a/tests/objects/bug783897.c-expected
+++ b/tests/objects/bug783897.c-expected
@@ -1,6 +1,13 @@
 /* objects_bug783897.c generated by valac, the Vala compiler
  * generated from objects_bug783897.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/objects/bug788964.c-expected b/tests/objects/bug788964.c-expected
index 2f2cca4bab5b43d6..2d615f282ac0b3b2 100644
--- a/tests/objects/bug788964.c-expected
+++ b/tests/objects/bug788964.c-expected
@@ -1,6 +1,13 @@
 /* objects_bug788964.c generated by valac, the Vala compiler
  * generated from objects_bug788964.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/bug795521.c-expected b/tests/objects/bug795521.c-expected
index 07a62749482115c5..70736eb78ad1c0e8 100644
--- a/tests/objects/bug795521.c-expected
+++ b/tests/objects/bug795521.c-expected
@@ -1,6 +1,13 @@
 /* objects_bug795521.c generated by valac, the Vala compiler
  * generated from objects_bug795521.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/chainup.c-expected b/tests/objects/chainup.c-expected
index a3d35c3efa974ab2..9a7fc598a413391c 100644
--- a/tests/objects/chainup.c-expected
+++ b/tests/objects/chainup.c-expected
@@ -1,6 +1,13 @@
 /* objects_chainup.c generated by valac, the Vala compiler
  * generated from objects_chainup.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdarg.h>
diff --git a/tests/objects/class-ccode-cprefix.c-expected b/tests/objects/class-ccode-cprefix.c-expected
index e2dbcc440559d143..ecc66a0732d18def 100644
--- a/tests/objects/class-ccode-cprefix.c-expected
+++ b/tests/objects/class-ccode-cprefix.c-expected
@@ -1,6 +1,13 @@
 /* objects_class_ccode_cprefix.c generated by valac, the Vala compiler
  * generated from objects_class_ccode_cprefix.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
 
diff --git a/tests/objects/class-destroysinstance.c-expected b/tests/objects/class-destroysinstance.c-expected
index 4f52cd7f71064631..88d5c77ffcc444a9 100644
--- a/tests/objects/class-destroysinstance.c-expected
+++ b/tests/objects/class-destroysinstance.c-expected
@@ -1,6 +1,13 @@
 /* objects_class_destroysinstance.c generated by valac, the Vala compiler
  * generated from objects_class_destroysinstance.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/objects/class-inner-types.c-expected b/tests/objects/class-inner-types.c-expected
index 110ad6abb8c87479..0bbe0da030bd467b 100644
--- a/tests/objects/class-inner-types.c-expected
+++ b/tests/objects/class-inner-types.c-expected
@@ -1,6 +1,13 @@
 /* objects_class_inner_types.c generated by valac, the Vala compiler
  * generated from objects_class_inner_types.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/class-new-no-override.c-expected b/tests/objects/class-new-no-override.c-expected
index 6d9dec170eaa5dec..830054734a34095c 100644
--- a/tests/objects/class-new-no-override.c-expected
+++ b/tests/objects/class-new-no-override.c-expected
@@ -1,6 +1,13 @@
 /* objects_class_new_no_override.c generated by valac, the Vala compiler
  * generated from objects_class_new_no_override.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/objects/class-partial-nested.c-expected b/tests/objects/class-partial-nested.c-expected
index c0ddeafd9d3a3612..d96b1617bef12955 100644
--- a/tests/objects/class-partial-nested.c-expected
+++ b/tests/objects/class-partial-nested.c-expected
@@ -1,6 +1,13 @@
 /* objects_class_partial_nested.c generated by valac, the Vala compiler
  * generated from objects_class_partial_nested.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/class-partial.c-expected b/tests/objects/class-partial.c-expected
index 0b9f77d2f8551aa5..43c018fa26823947 100644
--- a/tests/objects/class-partial.c-expected
+++ b/tests/objects/class-partial.c-expected
@@ -1,6 +1,13 @@
 /* objects_class_partial.c generated by valac, the Vala compiler
  * generated from objects_class_partial.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/objects/class-ref-void.c-expected b/tests/objects/class-ref-void.c-expected
index d0038ab464dc4310..01fe34c088bb4890 100644
--- a/tests/objects/class-ref-void.c-expected
+++ b/tests/objects/class-ref-void.c-expected
@@ -1,6 +1,13 @@
 /* objects_class_ref_void.c generated by valac, the Vala compiler
  * generated from objects_class_ref_void.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/objects/class-vfunc-base-access.c-expected b/tests/objects/class-vfunc-base-access.c-expected
index 2ad5c9cdf383b852..3a52e3016231c820 100644
--- a/tests/objects/class-vfunc-base-access.c-expected
+++ b/tests/objects/class-vfunc-base-access.c-expected
@@ -1,6 +1,13 @@
 /* objects_class_vfunc_base_access.c generated by valac, the Vala compiler
  * generated from objects_class_vfunc_base_access.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/class_only.c-expected b/tests/objects/class_only.c-expected
index b4e6d87cc2762c4a..50d916c7ccfd86fd 100644
--- a/tests/objects/class_only.c-expected
+++ b/tests/objects/class_only.c-expected
@@ -1,6 +1,13 @@
 /* objects_class_only.c generated by valac, the Vala compiler
  * generated from objects_class_only.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
 
diff --git a/tests/objects/classes-implicit-implementation.c-expected b/tests/objects/classes-implicit-implementation.c-expected
index 3008fbc0107c7963..d6055875e94fa7cb 100644
--- a/tests/objects/classes-implicit-implementation.c-expected
+++ b/tests/objects/classes-implicit-implementation.c-expected
@@ -1,6 +1,13 @@
 /* objects_classes_implicit_implementation.c generated by valac, the Vala compiler
  * generated from objects_classes_implicit_implementation.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/objects/classes-interfaces-virtuals.c-expected b/tests/objects/classes-interfaces-virtuals.c-expected
index a770c2b32deb9a50..9151e04d0ad66c25 100644
--- a/tests/objects/classes-interfaces-virtuals.c-expected
+++ b/tests/objects/classes-interfaces-virtuals.c-expected
@@ -1,6 +1,13 @@
 /* objects_classes_interfaces_virtuals.c generated by valac, the Vala compiler
  * generated from objects_classes_interfaces_virtuals.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/objects/classes-interfaces.c-expected b/tests/objects/classes-interfaces.c-expected
index fce71f4e7ace44ef..4a3566063e3f29ff 100644
--- a/tests/objects/classes-interfaces.c-expected
+++ b/tests/objects/classes-interfaces.c-expected
@@ -1,6 +1,13 @@
 /* objects_classes_interfaces.c generated by valac, the Vala compiler
  * generated from objects_classes_interfaces.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/objects/classes.c-expected b/tests/objects/classes.c-expected
index afe167367a783d70..19aaaecdd1762df9 100644
--- a/tests/objects/classes.c-expected
+++ b/tests/objects/classes.c-expected
@@ -1,6 +1,13 @@
 /* objects_classes.c generated by valac, the Vala compiler
  * generated from objects_classes.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <stdio.h>
 #include <glib-object.h>
diff --git a/tests/objects/compact-class-custom-ref.c-expected b/tests/objects/compact-class-custom-ref.c-expected
index 7d15c46c78b179cd..041b1b2e8cb140c1 100644
--- a/tests/objects/compact-class-custom-ref.c-expected
+++ b/tests/objects/compact-class-custom-ref.c-expected
@@ -1,6 +1,13 @@
 /* objects_compact_class_custom_ref.c generated by valac, the Vala compiler
  * generated from objects_compact_class_custom_ref.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/objects/compact-class-destructor.c-expected b/tests/objects/compact-class-destructor.c-expected
index 7214f19d81ed7a69..abfd887fca54eecc 100644
--- a/tests/objects/compact-class-destructor.c-expected
+++ b/tests/objects/compact-class-destructor.c-expected
@@ -1,6 +1,13 @@
 /* objects_compact_class_destructor.c generated by valac, the Vala compiler
  * generated from objects_compact_class_destructor.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/compact-class-refcount.c-expected b/tests/objects/compact-class-refcount.c-expected
index 1d0cf67ee00ed543..ff344ad46b04cfd1 100644
--- a/tests/objects/compact-class-refcount.c-expected
+++ b/tests/objects/compact-class-refcount.c-expected
@@ -1,6 +1,13 @@
 /* objects_compact_class_refcount.c generated by valac, the Vala compiler
  * generated from objects_compact_class_refcount.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/objects/compact-class.c-expected b/tests/objects/compact-class.c-expected
index 4a2ab95f9696c992..1568ae26c0eee8f4 100644
--- a/tests/objects/compact-class.c-expected
+++ b/tests/objects/compact-class.c-expected
@@ -1,6 +1,13 @@
 /* objects_compact_class.c generated by valac, the Vala compiler
  * generated from objects_compact_class.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/objects/constructor-inner-error.c-expected b/tests/objects/constructor-inner-error.c-expected
index 702c79511b755047..bdb8273f24bb9254 100644
--- a/tests/objects/constructor-inner-error.c-expected
+++ b/tests/objects/constructor-inner-error.c-expected
@@ -1,6 +1,13 @@
 /* objects_constructor_inner_error.c generated by valac, the Vala compiler
  * generated from objects_constructor_inner_error.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/objects/constructor-variadic.c-expected b/tests/objects/constructor-variadic.c-expected
index 522fb8325d86e993..932c2f5d3ca6c140 100644
--- a/tests/objects/constructor-variadic.c-expected
+++ b/tests/objects/constructor-variadic.c-expected
@@ -1,6 +1,13 @@
 /* objects_constructor_variadic.c generated by valac, the Vala compiler
  * generated from objects_constructor_variadic.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/constructors.c-expected b/tests/objects/constructors.c-expected
index a928d36fafc8e8cb..6eeed2630a9ea3ea 100644
--- a/tests/objects/constructors.c-expected
+++ b/tests/objects/constructors.c-expected
@@ -1,6 +1,13 @@
 /* objects_constructors.c generated by valac, the Vala compiler
  * generated from objects_constructors.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/destructors.c-expected b/tests/objects/destructors.c-expected
index a3e969bef7382682..6b7b91d451168fc8 100644
--- a/tests/objects/destructors.c-expected
+++ b/tests/objects/destructors.c-expected
@@ -1,6 +1,13 @@
 /* objects_destructors.c generated by valac, the Vala compiler
  * generated from objects_destructors.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/dynamic.c-expected b/tests/objects/dynamic.c-expected
index c1a3aed501b65e5d..f1fefc6482ac556e 100644
--- a/tests/objects/dynamic.c-expected
+++ b/tests/objects/dynamic.c-expected
@@ -1,6 +1,13 @@
 /* objects_dynamic.c generated by valac, the Vala compiler
  * generated from objects_dynamic.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/fields.c-expected b/tests/objects/fields.c-expected
index c0fdf2f7cb268e5a..f366bc7c1b190321 100644
--- a/tests/objects/fields.c-expected
+++ b/tests/objects/fields.c-expected
@@ -1,6 +1,13 @@
 /* objects_fields.c generated by valac, the Vala compiler
  * generated from objects_fields.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/generics.c-expected b/tests/objects/generics.c-expected
index 09b90174acfd7fe1..aca7fdac597b2b35 100644
--- a/tests/objects/generics.c-expected
+++ b/tests/objects/generics.c-expected
@@ -1,6 +1,13 @@
 /* objects_generics.c generated by valac, the Vala compiler
  * generated from objects_generics.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/gobject-class-lifetime.c-expected b/tests/objects/gobject-class-lifetime.c-expected
index d2c971e12fd0c476..a49c7377b5f45509 100644
--- a/tests/objects/gobject-class-lifetime.c-expected
+++ b/tests/objects/gobject-class-lifetime.c-expected
@@ -1,6 +1,13 @@
 /* objects_gobject_class_lifetime.c generated by valac, the Vala compiler
  * generated from objects_gobject_class_lifetime.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/objects/gsource.c-expected b/tests/objects/gsource.c-expected
index 3413e072676600b9..5d6e0a55d3a96cbb 100644
--- a/tests/objects/gsource.c-expected
+++ b/tests/objects/gsource.c-expected
@@ -1,6 +1,13 @@
 /* objects_gsource.c generated by valac, the Vala compiler
  * generated from objects_gsource.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/objects/gtype-class-lifetime.c-expected b/tests/objects/gtype-class-lifetime.c-expected
index ce13f2e2014aac59..5244a769f6159e59 100644
--- a/tests/objects/gtype-class-lifetime.c-expected
+++ b/tests/objects/gtype-class-lifetime.c-expected
@@ -1,6 +1,13 @@
 /* objects_gtype_class_lifetime.c generated by valac, the Vala compiler
  * generated from objects_gtype_class_lifetime.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/initially-unowned.c-expected b/tests/objects/initially-unowned.c-expected
index 3cc673fc005c0d65..52c477cbb8cd10bc 100644
--- a/tests/objects/initially-unowned.c-expected
+++ b/tests/objects/initially-unowned.c-expected
@@ -1,6 +1,13 @@
 /* objects_initially_unowned.c generated by valac, the Vala compiler
  * generated from objects_initially_unowned.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/instance-comparison.c-expected b/tests/objects/instance-comparison.c-expected
index 8119180765bd9bf2..c39c2caec3355ab8 100644
--- a/tests/objects/instance-comparison.c-expected
+++ b/tests/objects/instance-comparison.c-expected
@@ -1,6 +1,13 @@
 /* objects_instance_comparison.c generated by valac, the Vala compiler
  * generated from objects_instance_comparison.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/objects/interface-abstract-async-override.c-expected b/tests/objects/interface-abstract-async-override.c-expected
index 494585889f4afe82..563b81126b464e1e 100644
--- a/tests/objects/interface-abstract-async-override.c-expected
+++ b/tests/objects/interface-abstract-async-override.c-expected
@@ -1,6 +1,13 @@
 /* objects_interface_abstract_async_override.c generated by valac, the Vala compiler
  * generated from objects_interface_abstract_async_override.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/objects/interface-async-base-access.c-expected b/tests/objects/interface-async-base-access.c-expected
index a84c03a393bd0f9d..aa832d524a0e9525 100644
--- a/tests/objects/interface-async-base-access.c-expected
+++ b/tests/objects/interface-async-base-access.c-expected
@@ -1,6 +1,13 @@
 /* objects_interface_async_base_access.c generated by valac, the Vala compiler
  * generated from objects_interface_async_base_access.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/objects/interface-async-captured-generic.c-expected b/tests/objects/interface-async-captured-generic.c-expected
index 6c709b0bac795a9a..f029d2e618be6498 100644
--- a/tests/objects/interface-async-captured-generic.c-expected
+++ b/tests/objects/interface-async-captured-generic.c-expected
@@ -1,6 +1,13 @@
 /* objects_interface_async_captured_generic.c generated by valac, the Vala compiler
  * generated from objects_interface_async_captured_generic.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/objects/interface-base-access.c-expected b/tests/objects/interface-base-access.c-expected
index 185c70f2db18d71d..5f8fede33bad5bf5 100644
--- a/tests/objects/interface-base-access.c-expected
+++ b/tests/objects/interface-base-access.c-expected
@@ -1,6 +1,13 @@
 /* objects_interface_base_access.c generated by valac, the Vala compiler
  * generated from objects_interface_base_access.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/interface-generics.c-expected b/tests/objects/interface-generics.c-expected
index d6cd58a21ea399ec..20544b608fdc4dc4 100644
--- a/tests/objects/interface-generics.c-expected
+++ b/tests/objects/interface-generics.c-expected
@@ -1,6 +1,13 @@
 /* objects_interface_generics.c generated by valac, the Vala compiler
  * generated from objects_interface_generics.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/objects/interface-inner-types.c-expected b/tests/objects/interface-inner-types.c-expected
index cb7386ab2afd8ba7..9b96e97a0ec9cb7a 100644
--- a/tests/objects/interface-inner-types.c-expected
+++ b/tests/objects/interface-inner-types.c-expected
@@ -1,6 +1,13 @@
 /* objects_interface_inner_types.c generated by valac, the Vala compiler
  * generated from objects_interface_inner_types.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
 #include <glib.h>
diff --git a/tests/objects/interface-parameter-nowrapper.c-expected b/tests/objects/interface-parameter-nowrapper.c-expected
index 289a961564c25d3f..8136d36e18b853b1 100644
--- a/tests/objects/interface-parameter-nowrapper.c-expected
+++ b/tests/objects/interface-parameter-nowrapper.c-expected
@@ -1,6 +1,13 @@
 /* objects_interface_parameter_nowrapper.c generated by valac, the Vala compiler
  * generated from objects_interface_parameter_nowrapper.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/interface-property-base-access.c-expected b/tests/objects/interface-property-base-access.c-expected
index 5a71890760c8796a..78e12ad25864fc4d 100644
--- a/tests/objects/interface-property-base-access.c-expected
+++ b/tests/objects/interface-property-base-access.c-expected
@@ -1,6 +1,13 @@
 /* objects_interface_property_base_access.c generated by valac, the Vala compiler
  * generated from objects_interface_property_base_access.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/objects/interface-property-base-impl.c-expected b/tests/objects/interface-property-base-impl.c-expected
index 021cce6471e33e17..59eeed419b94d634 100644
--- a/tests/objects/interface-property-base-impl.c-expected
+++ b/tests/objects/interface-property-base-impl.c-expected
@@ -1,6 +1,13 @@
 /* objects_interface_property_base_impl.c generated by valac, the Vala compiler
  * generated from objects_interface_property_base_impl.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/objects/interface-property-delegate.c-expected b/tests/objects/interface-property-delegate.c-expected
index 919b29c944719995..b571eb09519a3018 100644
--- a/tests/objects/interface-property-delegate.c-expected
+++ b/tests/objects/interface-property-delegate.c-expected
@@ -1,6 +1,13 @@
 /* objects_interface_property_delegate.c generated by valac, the Vala compiler
  * generated from objects_interface_property_delegate.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/interface-property-override.c-expected b/tests/objects/interface-property-override.c-expected
index 8e10b48d8073abb8..6b8aa9e323491440 100644
--- a/tests/objects/interface-property-override.c-expected
+++ b/tests/objects/interface-property-override.c-expected
@@ -1,6 +1,13 @@
 /* objects_interface_property_override.c generated by valac, the Vala compiler
  * generated from objects_interface_property_override.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/interface-virtual-override.c-expected b/tests/objects/interface-virtual-override.c-expected
index 5181438c15d6b46a..6a4bf80a8982bee3 100644
--- a/tests/objects/interface-virtual-override.c-expected
+++ b/tests/objects/interface-virtual-override.c-expected
@@ -1,6 +1,13 @@
 /* objects_interface_virtual_override.c generated by valac, the Vala compiler
  * generated from objects_interface_virtual_override.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gio/gio.h>
diff --git a/tests/objects/interface_only.c-expected b/tests/objects/interface_only.c-expected
index ee32d2c568e1aabe..748896915f69e868 100644
--- a/tests/objects/interface_only.c-expected
+++ b/tests/objects/interface_only.c-expected
@@ -1,6 +1,13 @@
 /* objects_interface_only.c generated by valac, the Vala compiler
  * generated from objects_interface_only.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/objects/interfaces.c-expected b/tests/objects/interfaces.c-expected
index f5762fce1f25dc25..3facc61e382f39de 100644
--- a/tests/objects/interfaces.c-expected
+++ b/tests/objects/interfaces.c-expected
@@ -1,6 +1,13 @@
 /* objects_interfaces.c generated by valac, the Vala compiler
  * generated from objects_interfaces.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdio.h>
diff --git a/tests/objects/member-initializer-base-properties.c-expected b/tests/objects/member-initializer-base-properties.c-expected
index f5b763e4c06813ad..d70527146011ba95 100644
--- a/tests/objects/member-initializer-base-properties.c-expected
+++ b/tests/objects/member-initializer-base-properties.c-expected
@@ -1,6 +1,13 @@
 /* objects_member_initializer_base_properties.c generated by valac, the Vala compiler
  * generated from objects_member_initializer_base_properties.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/member-initializer-chained-2.c-expected b/tests/objects/member-initializer-chained-2.c-expected
index 6ea0aad0ce32169f..047ee6b5d7069a0f 100644
--- a/tests/objects/member-initializer-chained-2.c-expected
+++ b/tests/objects/member-initializer-chained-2.c-expected
@@ -1,6 +1,13 @@
 /* objects_member_initializer_chained_2.c generated by valac, the Vala compiler
  * generated from objects_member_initializer_chained_2.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/member-initializer-chained.c-expected b/tests/objects/member-initializer-chained.c-expected
index 1ea6a71a5789ad0f..0fffe977e5873ce1 100644
--- a/tests/objects/member-initializer-chained.c-expected
+++ b/tests/objects/member-initializer-chained.c-expected
@@ -1,6 +1,13 @@
 /* objects_member_initializer_chained.c generated by valac, the Vala compiler
  * generated from objects_member_initializer_chained.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/member-initializer-private.c-expected b/tests/objects/member-initializer-private.c-expected
index 9027b52e5a5d46e7..0f427ffee8693ce8 100644
--- a/tests/objects/member-initializer-private.c-expected
+++ b/tests/objects/member-initializer-private.c-expected
@@ -1,6 +1,13 @@
 /* objects_member_initializer_private.c generated by valac, the Vala compiler
  * generated from objects_member_initializer_private.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/member-initializer-property-owned-setter.c-expected b/tests/objects/member-initializer-property-owned-setter.c-expected
index 94e126c4b0ac5e61..581b6eb476cf8e0e 100644
--- a/tests/objects/member-initializer-property-owned-setter.c-expected
+++ b/tests/objects/member-initializer-property-owned-setter.c-expected
@@ -1,6 +1,13 @@
 /* objects_member_initializer_property_owned_setter.c generated by valac, the Vala compiler
  * generated from objects_member_initializer_property_owned_setter.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/member-initializer-property.c-expected b/tests/objects/member-initializer-property.c-expected
index 8cdaf3e4e23b9f65..18fa09598b4b5a5d 100644
--- a/tests/objects/member-initializer-property.c-expected
+++ b/tests/objects/member-initializer-property.c-expected
@@ -1,6 +1,13 @@
 /* objects_member_initializer_property.c generated by valac, the Vala compiler
  * generated from objects_member_initializer_property.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
 #include <glib.h>
diff --git a/tests/objects/member-initializer-protected.c-expected b/tests/objects/member-initializer-protected.c-expected
index 951bb1b0fc809d01..ca589219d643bf34 100644
--- a/tests/objects/member-initializer-protected.c-expected
+++ b/tests/objects/member-initializer-protected.c-expected
@@ -1,6 +1,13 @@
 /* objects_member_initializer_protected.c generated by valac, the Vala compiler
  * generated from objects_member_initializer_protected.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/methods.c-expected b/tests/objects/methods.c-expected
index 38321f5cb875ba68..d1deeb95d72888f5 100644
--- a/tests/objects/methods.c-expected
+++ b/tests/objects/methods.c-expected
@@ -1,6 +1,13 @@
 /* objects_methods.c generated by valac, the Vala compiler
  * generated from objects_methods.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdio.h>
diff --git a/tests/objects/paramspec.c-expected b/tests/objects/paramspec.c-expected
index da4999822c8e4022..0d7117571ee0130f 100644
--- a/tests/objects/paramspec.c-expected
+++ b/tests/objects/paramspec.c-expected
@@ -1,6 +1,13 @@
 /* objects_paramspec.c generated by valac, the Vala compiler
  * generated from objects_paramspec.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/objects/plugin-module-init.c-expected b/tests/objects/plugin-module-init.c-expected
index aeffdff2f1da340f..d8571e9e152373b5 100644
--- a/tests/objects/plugin-module-init.c-expected
+++ b/tests/objects/plugin-module-init.c-expected
@@ -1,6 +1,13 @@
 /* objects_plugin_module_init.c generated by valac, the Vala compiler
  * generated from objects_plugin_module_init.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/objects/properties.c-expected b/tests/objects/properties.c-expected
index 22ed9869b4500cd2..9f0108a45441c8cc 100644
--- a/tests/objects/properties.c-expected
+++ b/tests/objects/properties.c-expected
@@ -1,6 +1,13 @@
 /* objects_properties.c generated by valac, the Vala compiler
  * generated from objects_properties.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/objects/property-array-length.c-expected b/tests/objects/property-array-length.c-expected
index e41c57e995d39232..0a76ec655fc71b54 100644
--- a/tests/objects/property-array-length.c-expected
+++ b/tests/objects/property-array-length.c-expected
@@ -1,6 +1,13 @@
 /* objects_property_array_length.c generated by valac, the Vala compiler
  * generated from objects_property_array_length.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <gio/gio.h>
 
diff --git a/tests/objects/property-array.c-expected b/tests/objects/property-array.c-expected
index 8f9a7bf85b00d496..31700117da47fa1b 100644
--- a/tests/objects/property-array.c-expected
+++ b/tests/objects/property-array.c-expected
@@ -1,6 +1,13 @@
 /* objects_property_array.c generated by valac, the Vala compiler
  * generated from objects_property_array.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/objects/property-base-access.c-expected b/tests/objects/property-base-access.c-expected
index f36956810b0bb256..3cac9900b578ecd6 100644
--- a/tests/objects/property-base-access.c-expected
+++ b/tests/objects/property-base-access.c-expected
@@ -1,6 +1,13 @@
 /* objects_property_base_access.c generated by valac, the Vala compiler
  * generated from objects_property_base_access.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/property-construct-only.c-expected b/tests/objects/property-construct-only.c-expected
index a38d8885ac43b5f4..69f3a3502b6c4d4c 100644
--- a/tests/objects/property-construct-only.c-expected
+++ b/tests/objects/property-construct-only.c-expected
@@ -1,6 +1,13 @@
 /* objects_property_construct_only.c generated by valac, the Vala compiler
  * generated from objects_property_construct_only.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/property-delegate-owned.c-expected b/tests/objects/property-delegate-owned.c-expected
index 7334eb6969eb08a2..12f50b378aa1be97 100644
--- a/tests/objects/property-delegate-owned.c-expected
+++ b/tests/objects/property-delegate-owned.c-expected
@@ -1,6 +1,13 @@
 /* objects_property_delegate_owned.c generated by valac, the Vala compiler
  * generated from objects_property_delegate_owned.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/property-delegate.c-expected b/tests/objects/property-delegate.c-expected
index c8be81390b4f9d63..ea56526a1f2fb2e8 100644
--- a/tests/objects/property-delegate.c-expected
+++ b/tests/objects/property-delegate.c-expected
@@ -1,6 +1,13 @@
 /* objects_property_delegate.c generated by valac, the Vala compiler
  * generated from objects_property_delegate.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/objects/property-dynamic-type-inference.c-expected b/tests/objects/property-dynamic-type-inference.c-expected
index c8e9cd5db9187731..d29b9865f1dbb410 100644
--- a/tests/objects/property-dynamic-type-inference.c-expected
+++ b/tests/objects/property-dynamic-type-inference.c-expected
@@ -1,6 +1,13 @@
 /* objects_property_dynamic_type_inference.c generated by valac, the Vala compiler
  * generated from objects_property_dynamic_type_inference.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/objects/property-enum-nullable.c-expected b/tests/objects/property-enum-nullable.c-expected
index 38b6bf2d82215a7c..4a701eb2f722c155 100644
--- a/tests/objects/property-enum-nullable.c-expected
+++ b/tests/objects/property-enum-nullable.c-expected
@@ -1,6 +1,13 @@
 /* objects_property_enum_nullable.c generated by valac, the Vala compiler
  * generated from objects_property_enum_nullable.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/objects/property-enum.c-expected b/tests/objects/property-enum.c-expected
index b46b26cb46499cff..d6faa7be088cdcff 100644
--- a/tests/objects/property-enum.c-expected
+++ b/tests/objects/property-enum.c-expected
@@ -1,6 +1,13 @@
 /* objects_property_enum.c generated by valac, the Vala compiler
  * generated from objects_property_enum.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/property-error.c-expected b/tests/objects/property-error.c-expected
index feffb48902fe864f..712f4b598e2329ed 100644
--- a/tests/objects/property-error.c-expected
+++ b/tests/objects/property-error.c-expected
@@ -1,6 +1,13 @@
 /* objects_property_error.c generated by valac, the Vala compiler
  * generated from objects_property_error.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/property-gboxed-nullable.c-expected b/tests/objects/property-gboxed-nullable.c-expected
index 1438750ac3c410f4..55f2198904717e4e 100644
--- a/tests/objects/property-gboxed-nullable.c-expected
+++ b/tests/objects/property-gboxed-nullable.c-expected
@@ -1,6 +1,13 @@
 /* objects_property_gboxed_nullable.c generated by valac, the Vala compiler
  * generated from objects_property_gboxed_nullable.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/property-notify-owned-getter.c-expected b/tests/objects/property-notify-owned-getter.c-expected
index b287aad858c5f319..d1b7bbc0e22fbff3 100644
--- a/tests/objects/property-notify-owned-getter.c-expected
+++ b/tests/objects/property-notify-owned-getter.c-expected
@@ -1,6 +1,13 @@
 /* objects_property_notify_owned_getter.c generated by valac, the Vala compiler
  * generated from objects_property_notify_owned_getter.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/property-notify.c-expected b/tests/objects/property-notify.c-expected
index 093715144dcbb8a6..95f667b2b0ab66ef 100644
--- a/tests/objects/property-notify.c-expected
+++ b/tests/objects/property-notify.c-expected
@@ -1,6 +1,13 @@
 /* objects_property_notify.c generated by valac, the Vala compiler
  * generated from objects_property_notify.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/property-ownership.c-expected b/tests/objects/property-ownership.c-expected
index 8b353c1f52e5ea36..96e76ae68c7a9707 100644
--- a/tests/objects/property-ownership.c-expected
+++ b/tests/objects/property-ownership.c-expected
@@ -1,6 +1,13 @@
 /* objects_property_ownership.c generated by valac, the Vala compiler
  * generated from objects_property_ownership.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/property-read-only-auto.c-expected b/tests/objects/property-read-only-auto.c-expected
index ad5ba37e7536cecc..e13eee707134a66b 100644
--- a/tests/objects/property-read-only-auto.c-expected
+++ b/tests/objects/property-read-only-auto.c-expected
@@ -1,6 +1,13 @@
 /* objects_property_read_only_auto.c generated by valac, the Vala compiler
  * generated from objects_property_read_only_auto.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/property-real-struct-assignment.c-expected b/tests/objects/property-real-struct-assignment.c-expected
index 7f4b4e7889ad1094..8255a49c38858bda 100644
--- a/tests/objects/property-real-struct-assignment.c-expected
+++ b/tests/objects/property-real-struct-assignment.c-expected
@@ -1,6 +1,13 @@
 /* objects_property_real_struct_assignment.c generated by valac, the Vala compiler
  * generated from objects_property_real_struct_assignment.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/property-simple-type-struct-nullable.c-expected b/tests/objects/property-simple-type-struct-nullable.c-expected
index ebed89e1890c30d4..6dc783eb50240ad7 100644
--- a/tests/objects/property-simple-type-struct-nullable.c-expected
+++ b/tests/objects/property-simple-type-struct-nullable.c-expected
@@ -1,6 +1,13 @@
 /* objects_property_simple_type_struct_nullable.c generated by valac, the Vala compiler
  * generated from objects_property_simple_type_struct_nullable.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/objects/property-static.c-expected b/tests/objects/property-static.c-expected
index 1d57142f60b7cefc..c550743ef8e0a69c 100644
--- a/tests/objects/property-static.c-expected
+++ b/tests/objects/property-static.c-expected
@@ -1,6 +1,13 @@
 /* objects_property_static.c generated by valac, the Vala compiler
  * generated from objects_property_static.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/property-struct-no-gtype.c-expected b/tests/objects/property-struct-no-gtype.c-expected
index c6a88a7bf25e7fc0..447a5a331f84fd9b 100644
--- a/tests/objects/property-struct-no-gtype.c-expected
+++ b/tests/objects/property-struct-no-gtype.c-expected
@@ -1,6 +1,13 @@
 /* objects_property_struct_no_gtype.c generated by valac, the Vala compiler
  * generated from objects_property_struct_no_gtype.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/objects/property-struct.c-expected b/tests/objects/property-struct.c-expected
index 42da46c8f0c9f243..6e8d0a2b905f7f24 100644
--- a/tests/objects/property-struct.c-expected
+++ b/tests/objects/property-struct.c-expected
@@ -1,6 +1,13 @@
 /* objects_property_struct.c generated by valac, the Vala compiler
  * generated from objects_property_struct.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/property-strv-noaccessor.c-expected b/tests/objects/property-strv-noaccessor.c-expected
index 7443e002e570f2ca..5efb06b4cdbf2c08 100644
--- a/tests/objects/property-strv-noaccessor.c-expected
+++ b/tests/objects/property-strv-noaccessor.c-expected
@@ -1,6 +1,13 @@
 /* objects_property_strv_noaccessor.c generated by valac, the Vala compiler
  * generated from objects_property_strv_noaccessor.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/regex.c-expected b/tests/objects/regex.c-expected
index 3c05606fdb419860..c70373b8b4d0d4fd 100644
--- a/tests/objects/regex.c-expected
+++ b/tests/objects/regex.c-expected
@@ -1,6 +1,13 @@
 /* objects_regex.c generated by valac, the Vala compiler
  * generated from objects_regex.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <stdlib.h>
diff --git a/tests/objects/signals-default-class-handler.c-expected b/tests/objects/signals-default-class-handler.c-expected
index 55ee90c32da56199..01c24c7adae3020b 100644
--- a/tests/objects/signals-default-class-handler.c-expected
+++ b/tests/objects/signals-default-class-handler.c-expected
@@ -1,6 +1,13 @@
 /* objects_signals_default_class_handler.c generated by valac, the Vala compiler
  * generated from objects_signals_default_class_handler.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/signals-delegate-parameter.c-expected b/tests/objects/signals-delegate-parameter.c-expected
index a2dbe9af00b3749d..e9121fc986167f77 100644
--- a/tests/objects/signals-delegate-parameter.c-expected
+++ b/tests/objects/signals-delegate-parameter.c-expected
@@ -1,6 +1,13 @@
 /* objects_signals_delegate_parameter.c generated by valac, the Vala compiler
  * generated from objects_signals_delegate_parameter.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/objects/signals-delegate.c-expected b/tests/objects/signals-delegate.c-expected
index ee1bc862a8c5ce36..d01c552630fa6920 100644
--- a/tests/objects/signals-delegate.c-expected
+++ b/tests/objects/signals-delegate.c-expected
@@ -1,6 +1,13 @@
 /* objects_signals_delegate.c generated by valac, the Vala compiler
  * generated from objects_signals_delegate.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/objects/signals-dynamic-emit.c-expected b/tests/objects/signals-dynamic-emit.c-expected
index 7c71e3b42f047be1..032d430193baaac8 100644
--- a/tests/objects/signals-dynamic-emit.c-expected
+++ b/tests/objects/signals-dynamic-emit.c-expected
@@ -1,6 +1,13 @@
 /* objects_signals_dynamic_emit.c generated by valac, the Vala compiler
  * generated from objects_signals_dynamic_emit.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/signals-emit.c-expected b/tests/objects/signals-emit.c-expected
index 3836abc87ac13c0c..461c43c809e43044 100644
--- a/tests/objects/signals-emit.c-expected
+++ b/tests/objects/signals-emit.c-expected
@@ -1,6 +1,13 @@
 /* objects_signals_emit.c generated by valac, the Vala compiler
  * generated from objects_signals_emit.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/objects/signals-enum-marshal.c-expected b/tests/objects/signals-enum-marshal.c-expected
index 4158246a5306873c..0905dc34c15cb920 100644
--- a/tests/objects/signals-enum-marshal.c-expected
+++ b/tests/objects/signals-enum-marshal.c-expected
@@ -1,6 +1,13 @@
 /* objects_signals_enum_marshal.c generated by valac, the Vala compiler
  * generated from objects_signals_enum_marshal.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/signals-error-marshal.c-expected b/tests/objects/signals-error-marshal.c-expected
index 87270af12eeeb988..dd12c8e8fc189a1e 100644
--- a/tests/objects/signals-error-marshal.c-expected
+++ b/tests/objects/signals-error-marshal.c-expected
@@ -1,6 +1,13 @@
 /* objects_signals_error_marshal.c generated by valac, the Vala compiler
  * generated from objects_signals_error_marshal.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <string.h>
diff --git a/tests/objects/signals-fundamental-return.c-expected b/tests/objects/signals-fundamental-return.c-expected
index 0fee3f75fde6eee0..b9bbba21300d7a8f 100644
--- a/tests/objects/signals-fundamental-return.c-expected
+++ b/tests/objects/signals-fundamental-return.c-expected
@@ -1,6 +1,13 @@
 /* objects_signals_fundamental_return.c generated by valac, the Vala compiler
  * generated from objects_signals_fundamental_return.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
 #include <glib.h>
diff --git a/tests/objects/signals-generic-return.c-expected b/tests/objects/signals-generic-return.c-expected
index 0f156d2940e8667c..b9c36c7ce73604c7 100644
--- a/tests/objects/signals-generic-return.c-expected
+++ b/tests/objects/signals-generic-return.c-expected
@@ -1,6 +1,13 @@
 /* objects_signals_generic_return.c generated by valac, the Vala compiler
  * generated from objects_signals_generic_return.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/objects/signals-gobject-return.c-expected b/tests/objects/signals-gobject-return.c-expected
index a8cbb9597fe65c28..75499f3486b17490 100644
--- a/tests/objects/signals-gobject-return.c-expected
+++ b/tests/objects/signals-gobject-return.c-expected
@@ -1,6 +1,13 @@
 /* objects_signals_gobject_return.c generated by valac, the Vala compiler
  * generated from objects_signals_gobject_return.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/objects/signals-lambda-delegate-2.c-expected b/tests/objects/signals-lambda-delegate-2.c-expected
index 1ed3b85110f89992..ba10d8b3567bdae7 100644
--- a/tests/objects/signals-lambda-delegate-2.c-expected
+++ b/tests/objects/signals-lambda-delegate-2.c-expected
@@ -1,6 +1,13 @@
 /* objects_signals_lambda_delegate_2.c generated by valac, the Vala compiler
  * generated from objects_signals_lambda_delegate_2.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/objects/signals-lambda-delegate.c-expected b/tests/objects/signals-lambda-delegate.c-expected
index 0e6ba11c2ca6b9f5..fb8dae3f12b57f51 100644
--- a/tests/objects/signals-lambda-delegate.c-expected
+++ b/tests/objects/signals-lambda-delegate.c-expected
@@ -1,6 +1,13 @@
 /* objects_signals_lambda_delegate.c generated by valac, the Vala compiler
  * generated from objects_signals_lambda_delegate.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/signals-prototype-access.c-expected b/tests/objects/signals-prototype-access.c-expected
index 8c46ef8dd76cc473..557898d8cbc21dca 100644
--- a/tests/objects/signals-prototype-access.c-expected
+++ b/tests/objects/signals-prototype-access.c-expected
@@ -1,6 +1,13 @@
 /* objects_signals_prototype_access.c generated by valac, the Vala compiler
  * generated from objects_signals_prototype_access.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/signals-struct-return.c-expected b/tests/objects/signals-struct-return.c-expected
index d1c7ca1665021cd9..9d5b299363f56774 100644
--- a/tests/objects/signals-struct-return.c-expected
+++ b/tests/objects/signals-struct-return.c-expected
@@ -1,6 +1,13 @@
 /* objects_signals_struct_return.c generated by valac, the Vala compiler
  * generated from objects_signals_struct_return.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/signals-struct.c-expected b/tests/objects/signals-struct.c-expected
index efa6609b2ba2da91..e4d008d2a1ca2eca 100644
--- a/tests/objects/signals-struct.c-expected
+++ b/tests/objects/signals-struct.c-expected
@@ -1,6 +1,13 @@
 /* objects_signals_struct.c generated by valac, the Vala compiler
  * generated from objects_signals_struct.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/signals.c-expected b/tests/objects/signals.c-expected
index 2bf57024e0632b63..273a8bdc6751348f 100644
--- a/tests/objects/signals.c-expected
+++ b/tests/objects/signals.c-expected
@@ -1,6 +1,13 @@
 /* objects_signals.c generated by valac, the Vala compiler
  * generated from objects_signals.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <stdio.h>
diff --git a/tests/objects/simple-generics-chainup.c-expected b/tests/objects/simple-generics-chainup.c-expected
index a4831fc3332a71c2..7ec59db44e4456cd 100644
--- a/tests/objects/simple-generics-chainup.c-expected
+++ b/tests/objects/simple-generics-chainup.c-expected
@@ -1,6 +1,13 @@
 /* objects_simple_generics_chainup.c generated by valac, the Vala compiler
  * generated from objects_simple_generics_chainup.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/singleton.c-expected b/tests/objects/singleton.c-expected
index 5bb18fba630cb023..7d36431dd9a4b10a 100644
--- a/tests/objects/singleton.c-expected
+++ b/tests/objects/singleton.c-expected
@@ -1,6 +1,13 @@
 /* objects_singleton.c generated by valac, the Vala compiler
  * generated from objects_singleton.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/objects/test-025.c-expected b/tests/objects/test-025.c-expected
index b251c1c053c49745..4fb9e95c0b05aae0 100644
--- a/tests/objects/test-025.c-expected
+++ b/tests/objects/test-025.c-expected
@@ -1,6 +1,13 @@
 /* objects_test_025.c generated by valac, the Vala compiler
  * generated from objects_test_025.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdio.h>
 #include <glib.h>
diff --git a/tests/objects/test-026.c-expected b/tests/objects/test-026.c-expected
index 29be53b9b9fcde17..064763496ddb6a4a 100644
--- a/tests/objects/test-026.c-expected
+++ b/tests/objects/test-026.c-expected
@@ -1,6 +1,13 @@
 /* objects_test_026.c generated by valac, the Vala compiler
  * generated from objects_test_026.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdio.h>
diff --git a/tests/objects/test-029.c-expected b/tests/objects/test-029.c-expected
index d2942c7c30dbfea9..9a318cdb4c145ed8 100644
--- a/tests/objects/test-029.c-expected
+++ b/tests/objects/test-029.c-expected
@@ -1,6 +1,13 @@
 /* objects_test_029.c generated by valac, the Vala compiler
  * generated from objects_test_029.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdio.h>
diff --git a/tests/objects/test-034.c-expected b/tests/objects/test-034.c-expected
index 8dffb9553e4b93a1..7ae69504b60ba5c0 100644
--- a/tests/objects/test-034.c-expected
+++ b/tests/objects/test-034.c-expected
@@ -1,6 +1,13 @@
 /* objects_test_034.c generated by valac, the Vala compiler
  * generated from objects_test_034.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdio.h>
diff --git a/tests/objects/type-narrowing-by-precondition.c-expected b/tests/objects/type-narrowing-by-precondition.c-expected
index 672d70d728731cb7..936c460040be5578 100644
--- a/tests/objects/type-narrowing-by-precondition.c-expected
+++ b/tests/objects/type-narrowing-by-precondition.c-expected
@@ -1,6 +1,13 @@
 /* objects_type_narrowing_by_precondition.c generated by valac, the Vala compiler
  * generated from objects_type_narrowing_by_precondition.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/type-narrowing-fallback.c-expected b/tests/objects/type-narrowing-fallback.c-expected
index ce85370f1aa39dab..120294884fa2ce31 100644
--- a/tests/objects/type-narrowing-fallback.c-expected
+++ b/tests/objects/type-narrowing-fallback.c-expected
@@ -1,6 +1,13 @@
 /* objects_type_narrowing_fallback.c generated by valac, the Vala compiler
  * generated from objects_type_narrowing_fallback.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/objects/type-narrowing.c-expected b/tests/objects/type-narrowing.c-expected
index 78d8f78ff5546975..5bde9c964be89161 100644
--- a/tests/objects/type-narrowing.c-expected
+++ b/tests/objects/type-narrowing.c-expected
@@ -1,6 +1,13 @@
 /* objects_type_narrowing.c generated by valac, the Vala compiler
  * generated from objects_type_narrowing.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/objects/with-expression.c-expected b/tests/objects/with-expression.c-expected
index 7d8bdb913b3c0554..005b875b1dba2f06 100644
--- a/tests/objects/with-expression.c-expected
+++ b/tests/objects/with-expression.c-expected
@@ -1,6 +1,13 @@
 /* objects_with_expression.c generated by valac, the Vala compiler
  * generated from objects_with_expression.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/with-instance.c-expected b/tests/objects/with-instance.c-expected
index 8efaf2072a2b4cab..74ee5c3a569d836f 100644
--- a/tests/objects/with-instance.c-expected
+++ b/tests/objects/with-instance.c-expected
@@ -1,6 +1,13 @@
 /* objects_with_instance.c generated by valac, the Vala compiler
  * generated from objects_with_instance.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/objects/with-nested-in-lambda.c-expected b/tests/objects/with-nested-in-lambda.c-expected
index 58969da425c9b1ba..cdd3eb4f8791b47c 100644
--- a/tests/objects/with-nested-in-lambda.c-expected
+++ b/tests/objects/with-nested-in-lambda.c-expected
@@ -1,6 +1,13 @@
 /* objects_with_nested_in_lambda.c generated by valac, the Vala compiler
  * generated from objects_with_nested_in_lambda.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/with-nested-method.c-expected b/tests/objects/with-nested-method.c-expected
index cfb09338fd876b22..25e659006dbeff6f 100644
--- a/tests/objects/with-nested-method.c-expected
+++ b/tests/objects/with-nested-method.c-expected
@@ -1,6 +1,13 @@
 /* objects_with_nested_method.c generated by valac, the Vala compiler
  * generated from objects_with_nested_method.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/with-nested-signal.c-expected b/tests/objects/with-nested-signal.c-expected
index 3d55f4e68a655395..51aeed684742ad5a 100644
--- a/tests/objects/with-nested-signal.c-expected
+++ b/tests/objects/with-nested-signal.c-expected
@@ -1,6 +1,13 @@
 /* objects_with_nested_signal.c generated by valac, the Vala compiler
  * generated from objects_with_nested_signal.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/with-nested-unambigous-signal.c-expected b/tests/objects/with-nested-unambigous-signal.c-expected
index f4f1f04c732191ee..4b830f695fb7dce0 100644
--- a/tests/objects/with-nested-unambigous-signal.c-expected
+++ b/tests/objects/with-nested-unambigous-signal.c-expected
@@ -1,6 +1,13 @@
 /* objects_with_nested_unambigous_signal.c generated by valac, the Vala compiler
  * generated from objects_with_nested_unambigous_signal.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/with-nested.c-expected b/tests/objects/with-nested.c-expected
index 29a34825876231ca..c9b84b90287f4b7b 100644
--- a/tests/objects/with-nested.c-expected
+++ b/tests/objects/with-nested.c-expected
@@ -1,6 +1,13 @@
 /* objects_with_nested.c generated by valac, the Vala compiler
  * generated from objects_with_nested.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/ordering/constant-class.c-expected b/tests/ordering/constant-class.c-expected
index c6ce5c2340de8c9d..48eac178c5010fc0 100644
--- a/tests/ordering/constant-class.c-expected
+++ b/tests/ordering/constant-class.c-expected
@@ -1,6 +1,13 @@
 /* ordering_constant_class.c generated by valac, the Vala compiler
  * generated from ordering_constant_class.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/ordering/constant-constant.c-expected b/tests/ordering/constant-constant.c-expected
index e42751a152cc26ab..96c4e9c7a38322c3 100644
--- a/tests/ordering/constant-constant.c-expected
+++ b/tests/ordering/constant-constant.c-expected
@@ -1,6 +1,13 @@
 /* ordering_constant_constant.c generated by valac, the Vala compiler
  * generated from ordering_constant_constant.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #define FOO 42
diff --git a/tests/ordering/constant-enum.c-expected b/tests/ordering/constant-enum.c-expected
index d21a63354d1fcc92..bb37eeebed925647 100644
--- a/tests/ordering/constant-enum.c-expected
+++ b/tests/ordering/constant-enum.c-expected
@@ -1,6 +1,13 @@
 /* ordering_constant_enum.c generated by valac, the Vala compiler
  * generated from ordering_constant_enum.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/ordering/constant-field.c-expected b/tests/ordering/constant-field.c-expected
index ffc093b52768cebc..57c093c619dcdafa 100644
--- a/tests/ordering/constant-field.c-expected
+++ b/tests/ordering/constant-field.c-expected
@@ -1,6 +1,13 @@
 /* ordering_constant_field.c generated by valac, the Vala compiler
  * generated from ordering_constant_field.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #define FOO 42
diff --git a/tests/ordering/constant-struct.c-expected b/tests/ordering/constant-struct.c-expected
index 79d558cfc8740c3c..439628a384db65a2 100644
--- a/tests/ordering/constant-struct.c-expected
+++ b/tests/ordering/constant-struct.c-expected
@@ -1,6 +1,13 @@
 /* ordering_constant_struct.c generated by valac, the Vala compiler
  * generated from ordering_constant_struct.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/ordering/delegate-class.c-expected b/tests/ordering/delegate-class.c-expected
index d128ee437d70936a..209ecb18ecd99e3f 100644
--- a/tests/ordering/delegate-class.c-expected
+++ b/tests/ordering/delegate-class.c-expected
@@ -1,6 +1,13 @@
 /* ordering_delegate_class.c generated by valac, the Vala compiler
  * generated from ordering_delegate_class.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/ordering/delegate-enum.c-expected b/tests/ordering/delegate-enum.c-expected
index 08c0cadf761b2f85..476e72397e381d9a 100644
--- a/tests/ordering/delegate-enum.c-expected
+++ b/tests/ordering/delegate-enum.c-expected
@@ -1,6 +1,13 @@
 /* ordering_delegate_enum.c generated by valac, the Vala compiler
  * generated from ordering_delegate_enum.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/ordering/delegate-interface.c-expected b/tests/ordering/delegate-interface.c-expected
index eb971637c8b2cdf9..ea2cfdcf88062871 100644
--- a/tests/ordering/delegate-interface.c-expected
+++ b/tests/ordering/delegate-interface.c-expected
@@ -1,6 +1,13 @@
 /* ordering_delegate_interface.c generated by valac, the Vala compiler
  * generated from ordering_delegate_interface.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/ordering/delegate-struct.c-expected b/tests/ordering/delegate-struct.c-expected
index b4630c7de4817028..6a508ea29bf31274 100644
--- a/tests/ordering/delegate-struct.c-expected
+++ b/tests/ordering/delegate-struct.c-expected
@@ -1,6 +1,13 @@
 /* ordering_delegate_struct.c generated by valac, the Vala compiler
  * generated from ordering_delegate_struct.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/ordering/struct-delegate.c-expected b/tests/ordering/struct-delegate.c-expected
index c2a0932e87ab1b23..6f7e10abd5ee5695 100644
--- a/tests/ordering/struct-delegate.c-expected
+++ b/tests/ordering/struct-delegate.c-expected
@@ -1,6 +1,13 @@
 /* ordering_struct_delegate.c generated by valac, the Vala compiler
  * generated from ordering_struct_delegate.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/parser-keep-going/member-initializer.c-expected b/tests/parser-keep-going/member-initializer.c-expected
index 912b045c91777d58..2549d1a241114d1c 100644
--- a/tests/parser-keep-going/member-initializer.c-expected
+++ b/tests/parser-keep-going/member-initializer.c-expected
@@ -1,6 +1,13 @@
 /* parser_keep_going_member_initializer.c generated by valac, the Vala compiler
  * generated from parser_keep_going_member_initializer.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/parser/array-length.c-expected b/tests/parser/array-length.c-expected
index 9ef0f8f97e061b27..9fe338f2967da4a2 100644
--- a/tests/parser/array-length.c-expected
+++ b/tests/parser/array-length.c-expected
@@ -1,6 +1,13 @@
 /* parser_array_length.c generated by valac, the Vala compiler
  * generated from parser_array_length.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/parser/assignment.c-expected b/tests/parser/assignment.c-expected
index 64aa5c6c6b225729..6bd313a64fd36da8 100644
--- a/tests/parser/assignment.c-expected
+++ b/tests/parser/assignment.c-expected
@@ -1,6 +1,13 @@
 /* parser_assignment.c generated by valac, the Vala compiler
  * generated from parser_assignment.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 static void _vala_main (void);
diff --git a/tests/parser/bug728574.c-expected b/tests/parser/bug728574.c-expected
index bbbc957670c2cc9a..fefef55e43cbe3f5 100644
--- a/tests/parser/bug728574.c-expected
+++ b/tests/parser/bug728574.c-expected
@@ -1,6 +1,13 @@
 /* parser_bug728574.c generated by valac, the Vala compiler
  * generated from parser_bug728574.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #define _g_regex_unref0(var) ((var == NULL) ? NULL : (var = (g_regex_unref (var), NULL)))
diff --git a/tests/parser/bug749576.c-expected b/tests/parser/bug749576.c-expected
index b483b0fc87c5f5d6..5af66ebe1335868e 100644
--- a/tests/parser/bug749576.c-expected
+++ b/tests/parser/bug749576.c-expected
@@ -1,6 +1,13 @@
 /* parser_bug749576.c generated by valac, the Vala compiler
  * generated from parser_bug749576.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/parser/chained-equality.c-expected b/tests/parser/chained-equality.c-expected
index 3e59b5d34668d132..8b414c13c739516b 100644
--- a/tests/parser/chained-equality.c-expected
+++ b/tests/parser/chained-equality.c-expected
@@ -1,6 +1,13 @@
 /* parser_chained_equality.c generated by valac, the Vala compiler
  * generated from parser_chained_equality.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/parser/continue-statement.c-expected b/tests/parser/continue-statement.c-expected
index 0c2386d3f6ad5816..381e18416b6564cb 100644
--- a/tests/parser/continue-statement.c-expected
+++ b/tests/parser/continue-statement.c-expected
@@ -1,6 +1,13 @@
 /* parser_continue_statement.c generated by valac, the Vala compiler
  * generated from parser_continue_statement.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #define _vala_assert(expr, msg) if G_LIKELY (expr) ; else g_assertion_message_expr (G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC, msg);
diff --git a/tests/parser/do-statement.c-expected b/tests/parser/do-statement.c-expected
index 57682cbb7dab1b89..08744528115e9b38 100644
--- a/tests/parser/do-statement.c-expected
+++ b/tests/parser/do-statement.c-expected
@@ -1,6 +1,13 @@
 /* parser_do_statement.c generated by valac, the Vala compiler
  * generated from parser_do_statement.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #define _vala_assert(expr, msg) if G_LIKELY (expr) ; else g_assertion_message_expr (G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC, msg);
diff --git a/tests/parser/foreach.c-expected b/tests/parser/foreach.c-expected
index 5d013475a51da034..1b6d2e13b22a5a46 100644
--- a/tests/parser/foreach.c-expected
+++ b/tests/parser/foreach.c-expected
@@ -1,6 +1,13 @@
 /* parser_foreach.c generated by valac, the Vala compiler
  * generated from parser_foreach.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/parser/local-variable-multi-one-line.c-expected b/tests/parser/local-variable-multi-one-line.c-expected
index 943cf79a88236fac..2c6be85fd8b29091 100644
--- a/tests/parser/local-variable-multi-one-line.c-expected
+++ b/tests/parser/local-variable-multi-one-line.c-expected
@@ -1,6 +1,13 @@
 /* parser_local_variable_multi_one_line.c generated by valac, the Vala compiler
  * generated from parser_local_variable_multi_one_line.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <string.h>
 
diff --git a/tests/parser/local-variable.c-expected b/tests/parser/local-variable.c-expected
index 1f8612827fc8f804..5e2c224a0292d13b 100644
--- a/tests/parser/local-variable.c-expected
+++ b/tests/parser/local-variable.c-expected
@@ -1,6 +1,13 @@
 /* parser_local_variable.c generated by valac, the Vala compiler
  * generated from parser_local_variable.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/parser/lock-statement.c-expected b/tests/parser/lock-statement.c-expected
index 6deb21ef321b74ea..06858a0d7d560c3d 100644
--- a/tests/parser/lock-statement.c-expected
+++ b/tests/parser/lock-statement.c-expected
@@ -1,6 +1,13 @@
 /* parser_lock_statement.c generated by valac, the Vala compiler
  * generated from parser_lock_statement.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/parser/main-block-minimal.c-expected b/tests/parser/main-block-minimal.c-expected
index a8b8a94dcc15a168..41ebf0492b3cde48 100644
--- a/tests/parser/main-block-minimal.c-expected
+++ b/tests/parser/main-block-minimal.c-expected
@@ -1,6 +1,13 @@
 /* parser_main_block_minimal.c generated by valac, the Vala compiler
  * generated from parser_main_block_minimal.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 static void _vala_main (void);
diff --git a/tests/parser/main-block.c-expected b/tests/parser/main-block.c-expected
index fcb0e57486c6005c..4785c3acd86f1724 100644
--- a/tests/parser/main-block.c-expected
+++ b/tests/parser/main-block.c-expected
@@ -1,6 +1,13 @@
 /* parser_main_block.c generated by valac, the Vala compiler
  * generated from parser_main_block.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #define _vala_assert(expr, msg) if G_LIKELY (expr) ; else g_assertion_message_expr (G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC, msg);
diff --git a/tests/parser/member-access-pointer.c-expected b/tests/parser/member-access-pointer.c-expected
index af66c6effe14fbf1..077203050f46355f 100644
--- a/tests/parser/member-access-pointer.c-expected
+++ b/tests/parser/member-access-pointer.c-expected
@@ -1,6 +1,13 @@
 /* parser_member_access_pointer.c generated by valac, the Vala compiler
  * generated from parser_member_access_pointer.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/parser/member-initializer-empty.c-expected b/tests/parser/member-initializer-empty.c-expected
index 6e82e37fdd5409e5..6fc2e7b3f27b4c13 100644
--- a/tests/parser/member-initializer-empty.c-expected
+++ b/tests/parser/member-initializer-empty.c-expected
@@ -1,6 +1,13 @@
 /* parser_member_initializer_empty.c generated by valac, the Vala compiler
  * generated from parser_member_initializer_empty.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/parser/member-initializer-trailing-comma.c-expected b/tests/parser/member-initializer-trailing-comma.c-expected
index 70c745aecd1d03f9..4c3fced7cac543b0 100644
--- a/tests/parser/member-initializer-trailing-comma.c-expected
+++ b/tests/parser/member-initializer-trailing-comma.c-expected
@@ -1,6 +1,13 @@
 /* parser_member_initializer_trailing_comma.c generated by valac, the Vala compiler
  * generated from parser_member_initializer_trailing_comma.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/parser/member-initializer.c-expected b/tests/parser/member-initializer.c-expected
index 2b018ebf6009c323..78e0de4e89feccda 100644
--- a/tests/parser/member-initializer.c-expected
+++ b/tests/parser/member-initializer.c-expected
@@ -1,6 +1,13 @@
 /* parser_member_initializer.c generated by valac, the Vala compiler
  * generated from parser_member_initializer.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/parser/namespaces.c-expected b/tests/parser/namespaces.c-expected
index 36cfb4b90024d904..ee4b6c83be55e014 100644
--- a/tests/parser/namespaces.c-expected
+++ b/tests/parser/namespaces.c-expected
@@ -1,6 +1,13 @@
 /* parser_namespaces.c generated by valac, the Vala compiler
  * generated from parser_namespaces.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
 #include <stdio.h>
diff --git a/tests/parser/preprocessor-glib.c-expected b/tests/parser/preprocessor-glib.c-expected
index 9300c6d8d8211414..2a631b2fb3c9caa4 100644
--- a/tests/parser/preprocessor-glib.c-expected
+++ b/tests/parser/preprocessor-glib.c-expected
@@ -1,6 +1,13 @@
 /* parser_preprocessor_glib.c generated by valac, the Vala compiler
  * generated from parser_preprocessor_glib.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #define _vala_assert(expr, msg) if G_LIKELY (expr) ; else g_assertion_message_expr (G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC, msg);
diff --git a/tests/parser/preprocessor-vala.c-expected b/tests/parser/preprocessor-vala.c-expected
index 7de470816a67ce49..977da110f38da14a 100644
--- a/tests/parser/preprocessor-vala.c-expected
+++ b/tests/parser/preprocessor-vala.c-expected
@@ -1,6 +1,13 @@
 /* parser_preprocessor_vala.c generated by valac, the Vala compiler
  * generated from parser_preprocessor_vala.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #define _vala_assert(expr, msg) if G_LIKELY (expr) ; else g_assertion_message_expr (G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC, msg);
diff --git a/tests/parser/preprocessor.c-expected b/tests/parser/preprocessor.c-expected
index 0d9cce314dd7dc99..ae339096568c38f9 100644
--- a/tests/parser/preprocessor.c-expected
+++ b/tests/parser/preprocessor.c-expected
@@ -1,6 +1,13 @@
 /* parser_preprocessor.c generated by valac, the Vala compiler
  * generated from parser_preprocessor.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #define _vala_assert(expr, msg) if G_LIKELY (expr) ; else g_assertion_message_expr (G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC, msg);
diff --git a/tests/parser/qualified-member-access.c-expected b/tests/parser/qualified-member-access.c-expected
index c18b53b062d905d3..d1e28857c0c402ad 100644
--- a/tests/parser/qualified-member-access.c-expected
+++ b/tests/parser/qualified-member-access.c-expected
@@ -1,6 +1,13 @@
 /* parser_qualified_member_access.c generated by valac, the Vala compiler
  * generated from parser_qualified_member_access.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/parser/qualified-symbol-access.c-expected b/tests/parser/qualified-symbol-access.c-expected
index 824787809bddcbf5..b8620caee2412e39 100644
--- a/tests/parser/qualified-symbol-access.c-expected
+++ b/tests/parser/qualified-symbol-access.c-expected
@@ -1,6 +1,13 @@
 /* parser_qualified_symbol_access.c generated by valac, the Vala compiler
  * generated from parser_qualified_symbol_access.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/parser/sealed-class.c-expected b/tests/parser/sealed-class.c-expected
index c8b4dca917cea64c..15c5826056875798 100644
--- a/tests/parser/sealed-class.c-expected
+++ b/tests/parser/sealed-class.c-expected
@@ -1,6 +1,13 @@
 /* parser_sealed_class.c generated by valac, the Vala compiler
  * generated from parser_sealed_class.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
 
diff --git a/tests/parser/statement-keyword-as-identifier.c-expected b/tests/parser/statement-keyword-as-identifier.c-expected
index 58860adbbc0962f3..8fe75d9f137866b9 100644
--- a/tests/parser/statement-keyword-as-identifier.c-expected
+++ b/tests/parser/statement-keyword-as-identifier.c-expected
@@ -1,6 +1,13 @@
 /* parser_statement_keyword_as_identifier.c generated by valac, the Vala compiler
  * generated from parser_statement_keyword_as_identifier.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #define _vala_assert(expr, msg) if G_LIKELY (expr) ; else g_assertion_message_expr (G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC, msg);
diff --git a/tests/parser/switch-statement.c-expected b/tests/parser/switch-statement.c-expected
index b1715aab276967f8..f610f1c1a6cf6e5e 100644
--- a/tests/parser/switch-statement.c-expected
+++ b/tests/parser/switch-statement.c-expected
@@ -1,6 +1,13 @@
 /* parser_switch_statement.c generated by valac, the Vala compiler
  * generated from parser_switch_statement.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/parser/template.c-expected b/tests/parser/template.c-expected
index 933aa14f54cbd1ab..2c893b2f5f8a9b80 100644
--- a/tests/parser/template.c-expected
+++ b/tests/parser/template.c-expected
@@ -1,6 +1,13 @@
 /* parser_template.c generated by valac, the Vala compiler
  * generated from parser_template.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/parser/tuple.c-expected b/tests/parser/tuple.c-expected
index 6271f3b19b7c2b5d..7312ae1ad1f01d8c 100644
--- a/tests/parser/tuple.c-expected
+++ b/tests/parser/tuple.c-expected
@@ -1,6 +1,13 @@
 /* parser_tuple.c generated by valac, the Vala compiler
  * generated from parser_tuple.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/parser/using-directive.c-expected b/tests/parser/using-directive.c-expected
index 1f10b8863b652c06..95faae4212d4a645 100644
--- a/tests/parser/using-directive.c-expected
+++ b/tests/parser/using-directive.c-expected
@@ -1,6 +1,13 @@
 /* parser_using_directive.c generated by valac, the Vala compiler
  * generated from parser_using_directive.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #if !defined(VALA_EXTERN)
 #if defined(_MSC_VER)
 #define VALA_EXTERN __declspec(dllexport) extern
diff --git a/tests/parser/var-type-dynamic.c-expected b/tests/parser/var-type-dynamic.c-expected
index 75eaaae572180e2e..dee56125a10f9574 100644
--- a/tests/parser/var-type-dynamic.c-expected
+++ b/tests/parser/var-type-dynamic.c-expected
@@ -1,6 +1,13 @@
 /* parser_var_type_dynamic.c generated by valac, the Vala compiler
  * generated from parser_var_type_dynamic.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/parser/var-type-nullable.c-expected b/tests/parser/var-type-nullable.c-expected
index 84096141ec23bee7..3888e2c9ee7ba17b 100644
--- a/tests/parser/var-type-nullable.c-expected
+++ b/tests/parser/var-type-nullable.c-expected
@@ -1,6 +1,13 @@
 /* parser_var_type_nullable.c generated by valac, the Vala compiler
  * generated from parser_var_type_nullable.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/parser/with-embedded.c-expected b/tests/parser/with-embedded.c-expected
index 29935c99e6b593a4..1b8d98f6fa9677f8 100644
--- a/tests/parser/with-embedded.c-expected
+++ b/tests/parser/with-embedded.c-expected
@@ -1,6 +1,13 @@
 /* parser_with_embedded.c generated by valac, the Vala compiler
  * generated from parser_with_embedded.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/parser/with-empty.c-expected b/tests/parser/with-empty.c-expected
index 63149d164dd85718..c7b4af2f2ec86305 100644
--- a/tests/parser/with-empty.c-expected
+++ b/tests/parser/with-empty.c-expected
@@ -1,6 +1,13 @@
 /* parser_with_empty.c generated by valac, the Vala compiler
  * generated from parser_with_empty.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 static void _vala_main (void);
diff --git a/tests/parser/yield-return.c-expected b/tests/parser/yield-return.c-expected
index 11a23c41ee9fbaa6..66a5edda6573f7b1 100644
--- a/tests/parser/yield-return.c-expected
+++ b/tests/parser/yield-return.c-expected
@@ -1,6 +1,13 @@
 /* parser_yield_return.c generated by valac, the Vala compiler
  * generated from parser_yield_return.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/pointers/bug590641.c-expected b/tests/pointers/bug590641.c-expected
index ec0d96a3cf1255ce..05ace504fd02595a 100644
--- a/tests/pointers/bug590641.c-expected
+++ b/tests/pointers/bug590641.c-expected
@@ -1,6 +1,13 @@
 /* pointers_bug590641.c generated by valac, the Vala compiler
  * generated from pointers_bug590641.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/pointers/delete.c-expected b/tests/pointers/delete.c-expected
index f0652e5619d4b691..0add448164f8f774 100644
--- a/tests/pointers/delete.c-expected
+++ b/tests/pointers/delete.c-expected
@@ -1,6 +1,13 @@
 /* pointers_delete.c generated by valac, the Vala compiler
  * generated from pointers_delete.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
 #include <glib.h>
diff --git a/tests/posix/arrays.c-expected b/tests/posix/arrays.c-expected
index b59712f6b07af91a..f9f2801ac357fd97 100644
--- a/tests/posix/arrays.c-expected
+++ b/tests/posix/arrays.c-expected
@@ -1,6 +1,13 @@
 /* posix_arrays.c generated by valac, the Vala compiler
  * generated from posix_arrays.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <assert.h>
 #include <stddef.h>
diff --git a/tests/posix/delegate_only.c-expected b/tests/posix/delegate_only.c-expected
index e9df8bb8cd49af40..f5db0e2cb42b6119 100644
--- a/tests/posix/delegate_only.c-expected
+++ b/tests/posix/delegate_only.c-expected
@@ -1,6 +1,13 @@
 /* posix_delegate_only.c generated by valac, the Vala compiler
  * generated from posix_delegate_only.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 typedef void (*FooFunc) (void* user_data);
 
 static void _vala_main (void);
diff --git a/tests/posix/empty-length-0.c-expected b/tests/posix/empty-length-0.c-expected
index b11d450f34fccbfb..5c1846f8a4be8282 100644
--- a/tests/posix/empty-length-0.c-expected
+++ b/tests/posix/empty-length-0.c-expected
@@ -1,6 +1,13 @@
 /* posix_empty_length_0.c generated by valac, the Vala compiler
  * generated from posix_empty_length_0.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <stddef.h>
diff --git a/tests/posix/enum-to-string.c-expected b/tests/posix/enum-to-string.c-expected
index ca84c862acbec90f..ba335ae961ef8b8a 100644
--- a/tests/posix/enum-to-string.c-expected
+++ b/tests/posix/enum-to-string.c-expected
@@ -1,6 +1,13 @@
 /* posix_enum_to_string.c generated by valac, the Vala compiler
  * generated from posix_enum_to_string.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <assert.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/posix/enum_only.c-expected b/tests/posix/enum_only.c-expected
index 7582787072435039..a2c66c296cd0711a 100644
--- a/tests/posix/enum_only.c-expected
+++ b/tests/posix/enum_only.c-expected
@@ -1,6 +1,13 @@
 /* posix_enum_only.c generated by valac, the Vala compiler
  * generated from posix_enum_only.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 typedef enum  {
 	FOO_BAR,
 	FOO_BAZ
diff --git a/tests/posix/string-concat.c-expected b/tests/posix/string-concat.c-expected
index 5c9e3b301184094a..06c073216dc2686a 100644
--- a/tests/posix/string-concat.c-expected
+++ b/tests/posix/string-concat.c-expected
@@ -1,6 +1,13 @@
 /* posix_string_concat.c generated by valac, the Vala compiler
  * generated from posix_string_concat.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <stddef.h>
diff --git a/tests/posix/string-printf.c-expected b/tests/posix/string-printf.c-expected
index c63c6e0fe37c2c69..79f01f2c6bd3e459 100644
--- a/tests/posix/string-printf.c-expected
+++ b/tests/posix/string-printf.c-expected
@@ -1,6 +1,13 @@
 /* posix_string_printf.c generated by valac, the Vala compiler
  * generated from posix_string_printf.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <stdio.h>
diff --git a/tests/posix/struct_only.c-expected b/tests/posix/struct_only.c-expected
index da17479a4df002aa..845580066bab742b 100644
--- a/tests/posix/struct_only.c-expected
+++ b/tests/posix/struct_only.c-expected
@@ -1,6 +1,13 @@
 /* posix_struct_only.c generated by valac, the Vala compiler
  * generated from posix_struct_only.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 
diff --git a/tests/resolver/peek-inner-types.c-expected b/tests/resolver/peek-inner-types.c-expected
index 11a862f44bab882c..93a1312ccf2aa11c 100644
--- a/tests/resolver/peek-inner-types.c-expected
+++ b/tests/resolver/peek-inner-types.c-expected
@@ -1,6 +1,13 @@
 /* resolver_peek_inner_types.c generated by valac, the Vala compiler
  * generated from resolver_peek_inner_types.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
 #include <glib.h>
diff --git a/tests/scanner/regex-escape-x.c-expected b/tests/scanner/regex-escape-x.c-expected
index e330cc0250e486f4..1cd64d90eb211501 100644
--- a/tests/scanner/regex-escape-x.c-expected
+++ b/tests/scanner/regex-escape-x.c-expected
@@ -1,6 +1,13 @@
 /* scanner_regex_escape_x.c generated by valac, the Vala compiler
  * generated from scanner_regex_escape_x.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #define _g_regex_unref0(var) ((var == NULL) ? NULL : (var = (g_regex_unref (var), NULL)))
diff --git a/tests/scanner/string-escape-x.c-expected b/tests/scanner/string-escape-x.c-expected
index 06567f0b3c24f6c0..0a1cb7530f3c8cd8 100644
--- a/tests/scanner/string-escape-x.c-expected
+++ b/tests/scanner/string-escape-x.c-expected
@@ -1,6 +1,13 @@
 /* scanner_string_escape_x.c generated by valac, the Vala compiler
  * generated from scanner_string_escape_x.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/semantic/assignment-same-variable.c-expected b/tests/semantic/assignment-same-variable.c-expected
index 8fa29a4b4cec4c7d..0703a9bce0dc71a1 100644
--- a/tests/semantic/assignment-same-variable.c-expected
+++ b/tests/semantic/assignment-same-variable.c-expected
@@ -1,6 +1,13 @@
 /* semantic_assignment_same_variable.c generated by valac, the Vala compiler
  * generated from semantic_assignment_same_variable.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/semantic/cast-void-not-allowed.c-expected b/tests/semantic/cast-void-not-allowed.c-expected
index 93f91458f2886875..a620fe1454b6c113 100644
--- a/tests/semantic/cast-void-not-allowed.c-expected
+++ b/tests/semantic/cast-void-not-allowed.c-expected
@@ -1,6 +1,13 @@
 /* semantic_cast_void_not_allowed.c generated by valac, the Vala compiler
  * generated from semantic_cast_void_not_allowed.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/semantic/class-opaque-automatic-property.c-expected b/tests/semantic/class-opaque-automatic-property.c-expected
index fbb7cb85c6310b8e..81d6de6c083f559f 100644
--- a/tests/semantic/class-opaque-automatic-property.c-expected
+++ b/tests/semantic/class-opaque-automatic-property.c-expected
@@ -1,6 +1,13 @@
 /* semantic_class_opaque_automatic_property.c generated by valac, the Vala compiler
  * generated from semantic_class_opaque_automatic_property.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/semantic/class-opaque.c-expected b/tests/semantic/class-opaque.c-expected
index 0a1252961eabbb82..e439f6005fd27915 100644
--- a/tests/semantic/class-opaque.c-expected
+++ b/tests/semantic/class-opaque.c-expected
@@ -1,6 +1,13 @@
 /* semantic_class_opaque.c generated by valac, the Vala compiler
  * generated from semantic_class_opaque.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/semantic/compare-type-check.c-expected b/tests/semantic/compare-type-check.c-expected
index 61bb0da0bad2250a..d7301016ffd99fe1 100644
--- a/tests/semantic/compare-type-check.c-expected
+++ b/tests/semantic/compare-type-check.c-expected
@@ -1,6 +1,13 @@
 /* semantic_compare_type_check.c generated by valac, the Vala compiler
  * generated from semantic_compare_type_check.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
 #include <glib.h>
diff --git a/tests/semantic/field-constant.c-expected b/tests/semantic/field-constant.c-expected
index 84d863ea1e543fe9..2106c009e2b2c6aa 100644
--- a/tests/semantic/field-constant.c-expected
+++ b/tests/semantic/field-constant.c-expected
@@ -1,6 +1,13 @@
 /* semantic_field_constant.c generated by valac, the Vala compiler
  * generated from semantic_field_constant.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <float.h>
 #include <math.h>
diff --git a/tests/semantic/floating-reference-base-method.c-expected b/tests/semantic/floating-reference-base-method.c-expected
index 77d97147b0815169..1f82b769fe4d9f3c 100644
--- a/tests/semantic/floating-reference-base-method.c-expected
+++ b/tests/semantic/floating-reference-base-method.c-expected
@@ -1,6 +1,13 @@
 /* semantic_floating_reference_base_method.c generated by valac, the Vala compiler
  * generated from semantic_floating_reference_base_method.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/semantic/floating-reference-error.c-expected b/tests/semantic/floating-reference-error.c-expected
index 5e582f5db91a74c5..d44e3d9a415828dc 100644
--- a/tests/semantic/floating-reference-error.c-expected
+++ b/tests/semantic/floating-reference-error.c-expected
@@ -1,6 +1,13 @@
 /* semantic_floating_reference_error.c generated by valac, the Vala compiler
  * generated from semantic_floating_reference_error.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <stdarg.h>
 
diff --git a/tests/semantic/floating-reference.c-expected b/tests/semantic/floating-reference.c-expected
index 685f20108a7e6d30..3fdfe48c7faed44d 100644
--- a/tests/semantic/floating-reference.c-expected
+++ b/tests/semantic/floating-reference.c-expected
@@ -1,6 +1,13 @@
 /* semantic_floating_reference.c generated by valac, the Vala compiler
  * generated from semantic_floating_reference.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/semantic/localvariable-var-pointer-initializer.c-expected b/tests/semantic/localvariable-var-pointer-initializer.c-expected
index 4b9b4c009be6f819..66aaadf60c1fd038 100644
--- a/tests/semantic/localvariable-var-pointer-initializer.c-expected
+++ b/tests/semantic/localvariable-var-pointer-initializer.c-expected
@@ -1,6 +1,13 @@
 /* semantic_localvariable_var_pointer_initializer.c generated by valac, the Vala compiler
  * generated from semantic_localvariable_var_pointer_initializer.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/semantic/member-access-static-transformed-qualified.c-expected b/tests/semantic/member-access-static-transformed-qualified.c-expected
index d81553866f7e3130..9ddf06b97c78b378 100644
--- a/tests/semantic/member-access-static-transformed-qualified.c-expected
+++ b/tests/semantic/member-access-static-transformed-qualified.c-expected
@@ -1,6 +1,13 @@
 /* semantic_member_access_static_transformed_qualified.c generated by valac, the Vala compiler
  * generated from semantic_member_access_static_transformed_qualified.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
 
diff --git a/tests/semantic/member-access-static-with-instance.c-expected b/tests/semantic/member-access-static-with-instance.c-expected
index fc27197c9f12f755..2a224c0a8f9a695e 100644
--- a/tests/semantic/member-access-static-with-instance.c-expected
+++ b/tests/semantic/member-access-static-with-instance.c-expected
@@ -1,6 +1,13 @@
 /* semantic_member_access_static_with_instance.c generated by valac, the Vala compiler
  * generated from semantic_member_access_static_with_instance.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/semantic/member-access-transformed-qualified.c-expected b/tests/semantic/member-access-transformed-qualified.c-expected
index 5b26dfc66e1ca9ab..161ab28a992b9f61 100644
--- a/tests/semantic/member-access-transformed-qualified.c-expected
+++ b/tests/semantic/member-access-transformed-qualified.c-expected
@@ -1,6 +1,13 @@
 /* semantic_member_access_transformed_qualified.c generated by valac, the Vala compiler
  * generated from semantic_member_access_transformed_qualified.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/semantic/unary-ref-in-initializer-list.c-expected b/tests/semantic/unary-ref-in-initializer-list.c-expected
index d4e004eee73a030d..e77acbbd19085a4f 100644
--- a/tests/semantic/unary-ref-in-initializer-list.c-expected
+++ b/tests/semantic/unary-ref-in-initializer-list.c-expected
@@ -1,6 +1,13 @@
 /* semantic_unary_ref_in_initializer_list.c generated by valac, the Vala compiler
  * generated from semantic_unary_ref_in_initializer_list.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/semantic/unary-ref-in-member-initializer.c-expected b/tests/semantic/unary-ref-in-member-initializer.c-expected
index 5799be9a040c7b42..e3a553e28a9f519e 100644
--- a/tests/semantic/unary-ref-in-member-initializer.c-expected
+++ b/tests/semantic/unary-ref-in-member-initializer.c-expected
@@ -1,6 +1,13 @@
 /* semantic_unary_ref_in_member_initializer.c generated by valac, the Vala compiler
  * generated from semantic_unary_ref_in_member_initializer.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/semantic/with-buildin.c-expected b/tests/semantic/with-buildin.c-expected
index a0a15512d5e49e7f..6263f02973e96cf4 100644
--- a/tests/semantic/with-buildin.c-expected
+++ b/tests/semantic/with-buildin.c-expected
@@ -1,6 +1,13 @@
 /* semantic_with_buildin.c generated by valac, the Vala compiler
  * generated from semantic_with_buildin.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdio.h>
 #include <glib.h>
 
diff --git a/tests/semantic/with-compact.c-expected b/tests/semantic/with-compact.c-expected
index aa892e2392d79853..4713faae5af6d427 100644
--- a/tests/semantic/with-compact.c-expected
+++ b/tests/semantic/with-compact.c-expected
@@ -1,6 +1,13 @@
 /* semantic_with_compact.c generated by valac, the Vala compiler
  * generated from semantic_with_compact.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/semantic/with-declaration-cast-type.c-expected b/tests/semantic/with-declaration-cast-type.c-expected
index 497e40268843b69f..e6dfe359a65e332f 100644
--- a/tests/semantic/with-declaration-cast-type.c-expected
+++ b/tests/semantic/with-declaration-cast-type.c-expected
@@ -1,6 +1,13 @@
 /* semantic_with_declaration_cast_type.c generated by valac, the Vala compiler
  * generated from semantic_with_declaration_cast_type.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
 
diff --git a/tests/semantic/with-declaration.c-expected b/tests/semantic/with-declaration.c-expected
index 3f0957f0545b5795..e793c111a082ed8a 100644
--- a/tests/semantic/with-declaration.c-expected
+++ b/tests/semantic/with-declaration.c-expected
@@ -1,6 +1,13 @@
 /* semantic_with_declaration.c generated by valac, the Vala compiler
  * generated from semantic_with_declaration.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/semantic/with-dereferenced-pointer.c-expected b/tests/semantic/with-dereferenced-pointer.c-expected
index 1faf737e2b483c2a..817f1ac018358556 100644
--- a/tests/semantic/with-dereferenced-pointer.c-expected
+++ b/tests/semantic/with-dereferenced-pointer.c-expected
@@ -1,6 +1,13 @@
 /* semantic_with_dereferenced_pointer.c generated by valac, the Vala compiler
  * generated from semantic_with_dereferenced_pointer.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/semantic/with-enum-member.c-expected b/tests/semantic/with-enum-member.c-expected
index d7347f70b3c61220..0a4939560841a0fd 100644
--- a/tests/semantic/with-enum-member.c-expected
+++ b/tests/semantic/with-enum-member.c-expected
@@ -1,6 +1,13 @@
 /* semantic_with_enum_member.c generated by valac, the Vala compiler
  * generated from semantic_with_enum_member.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/semantic/with-null.c-expected b/tests/semantic/with-null.c-expected
index 0d5488110fb4aa53..98cf9f0d92579b21 100644
--- a/tests/semantic/with-null.c-expected
+++ b/tests/semantic/with-null.c-expected
@@ -1,6 +1,13 @@
 /* semantic_with_null.c generated by valac, the Vala compiler
  * generated from semantic_with_null.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/semantic/with-string.c-expected b/tests/semantic/with-string.c-expected
index 7d80c4782967e2df..fc67ed8eef75ecce 100644
--- a/tests/semantic/with-string.c-expected
+++ b/tests/semantic/with-string.c-expected
@@ -1,6 +1,13 @@
 /* semantic_with_string.c generated by valac, the Vala compiler
  * generated from semantic_with_string.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/semantic/with-value.c-expected b/tests/semantic/with-value.c-expected
index 1f09b30727c1c4b7..b94b6f803bbcc356 100644
--- a/tests/semantic/with-value.c-expected
+++ b/tests/semantic/with-value.c-expected
@@ -1,6 +1,13 @@
 /* semantic_with_value.c generated by valac, the Vala compiler
  * generated from semantic_with_value.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/structs/bug530605.c-expected b/tests/structs/bug530605.c-expected
index ad65d7af3a54d564..f8b8e4f0269bdbdb 100644
--- a/tests/structs/bug530605.c-expected
+++ b/tests/structs/bug530605.c-expected
@@ -1,6 +1,13 @@
 /* structs_bug530605.c generated by valac, the Vala compiler
  * generated from structs_bug530605.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/structs/bug572091.c-expected b/tests/structs/bug572091.c-expected
index 8046ad9b74cbcd42..aed421fed5e79f08 100644
--- a/tests/structs/bug572091.c-expected
+++ b/tests/structs/bug572091.c-expected
@@ -1,6 +1,13 @@
 /* structs_bug572091.c generated by valac, the Vala compiler
  * generated from structs_bug572091.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/structs/bug583603.c-expected b/tests/structs/bug583603.c-expected
index 8bbabae5954963e0..dac46a99194770c7 100644
--- a/tests/structs/bug583603.c-expected
+++ b/tests/structs/bug583603.c-expected
@@ -1,6 +1,13 @@
 /* structs_bug583603.c generated by valac, the Vala compiler
  * generated from structs_bug583603.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/structs/bug595587.c-expected b/tests/structs/bug595587.c-expected
index 3d5f56781fc5f068..a70d85b2a1b9eef1 100644
--- a/tests/structs/bug595587.c-expected
+++ b/tests/structs/bug595587.c-expected
@@ -1,6 +1,13 @@
 /* structs_bug595587.c generated by valac, the Vala compiler
  * generated from structs_bug595587.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/structs/bug596144.c-expected b/tests/structs/bug596144.c-expected
index deb8529465c09b3c..1f7820d3b84efdd6 100644
--- a/tests/structs/bug596144.c-expected
+++ b/tests/structs/bug596144.c-expected
@@ -1,6 +1,13 @@
 /* structs_bug596144.c generated by valac, the Vala compiler
  * generated from structs_bug596144.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/structs/bug603056.c-expected b/tests/structs/bug603056.c-expected
index 7530689b91fadb06..55a04bd02d7790d3 100644
--- a/tests/structs/bug603056.c-expected
+++ b/tests/structs/bug603056.c-expected
@@ -1,6 +1,13 @@
 /* structs_bug603056.c generated by valac, the Vala compiler
  * generated from structs_bug603056.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/structs/bug606202.c-expected b/tests/structs/bug606202.c-expected
index 9bfe67888eefc64f..96d35cad1656d8d6 100644
--- a/tests/structs/bug606202.c-expected
+++ b/tests/structs/bug606202.c-expected
@@ -1,6 +1,13 @@
 /* structs_bug606202.c generated by valac, the Vala compiler
  * generated from structs_bug606202.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/structs/bug609642.c-expected b/tests/structs/bug609642.c-expected
index 9f5e0a43a53b19fe..0e4cb1d3ef67b8c9 100644
--- a/tests/structs/bug609642.c-expected
+++ b/tests/structs/bug609642.c-expected
@@ -1,6 +1,13 @@
 /* structs_bug609642.c generated by valac, the Vala compiler
  * generated from structs_bug609642.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/structs/bug613513.c-expected b/tests/structs/bug613513.c-expected
index f0af93b3896ea957..9b42bdc8bed4e5a0 100644
--- a/tests/structs/bug613513.c-expected
+++ b/tests/structs/bug613513.c-expected
@@ -1,6 +1,13 @@
 /* structs_bug613513.c generated by valac, the Vala compiler
  * generated from structs_bug613513.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/structs/bug613825.c-expected b/tests/structs/bug613825.c-expected
index fd6775b9d417036e..3edd9213036cc65c 100644
--- a/tests/structs/bug613825.c-expected
+++ b/tests/structs/bug613825.c-expected
@@ -1,6 +1,13 @@
 /* structs_bug613825.c generated by valac, the Vala compiler
  * generated from structs_bug613825.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/structs/bug621176.c-expected b/tests/structs/bug621176.c-expected
index 77cae89372772545..d3ab3b4460b6364c 100644
--- a/tests/structs/bug621176.c-expected
+++ b/tests/structs/bug621176.c-expected
@@ -1,6 +1,13 @@
 /* structs_bug621176.c generated by valac, the Vala compiler
  * generated from structs_bug621176.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/structs/bug622422.c-expected b/tests/structs/bug622422.c-expected
index 561b64dd1c633a9e..61e2b8a0dda5cb96 100644
--- a/tests/structs/bug622422.c-expected
+++ b/tests/structs/bug622422.c-expected
@@ -1,6 +1,13 @@
 /* structs_bug622422.c generated by valac, the Vala compiler
  * generated from structs_bug622422.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/structs/bug623092.c-expected b/tests/structs/bug623092.c-expected
index 003620863f304f91..17c30733f3338135 100644
--- a/tests/structs/bug623092.c-expected
+++ b/tests/structs/bug623092.c-expected
@@ -1,6 +1,13 @@
 /* structs_bug623092.c generated by valac, the Vala compiler
  * generated from structs_bug623092.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/structs/bug651441.c-expected b/tests/structs/bug651441.c-expected
index 05d39686026da9d2..b7018986cd91cdb3 100644
--- a/tests/structs/bug651441.c-expected
+++ b/tests/structs/bug651441.c-expected
@@ -1,6 +1,13 @@
 /* structs_bug651441.c generated by valac, the Vala compiler
  * generated from structs_bug651441.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/structs/bug654646.c-expected b/tests/structs/bug654646.c-expected
index ac2e178a4e95793b..7720f07415731979 100644
--- a/tests/structs/bug654646.c-expected
+++ b/tests/structs/bug654646.c-expected
@@ -1,6 +1,13 @@
 /* structs_bug654646.c generated by valac, the Vala compiler
  * generated from structs_bug654646.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <stdarg.h>
 
diff --git a/tests/structs/bug654753.c-expected b/tests/structs/bug654753.c-expected
index 4c60a22acd3f19fc..1a05c71d15c8d9e8 100644
--- a/tests/structs/bug654753.c-expected
+++ b/tests/structs/bug654753.c-expected
@@ -1,6 +1,13 @@
 /* structs_bug654753.c generated by valac, the Vala compiler
  * generated from structs_bug654753.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/structs/bug656693.c-expected b/tests/structs/bug656693.c-expected
index 392fe9d3b91860a5..a7688f3663139d5b 100644
--- a/tests/structs/bug656693.c-expected
+++ b/tests/structs/bug656693.c-expected
@@ -1,6 +1,13 @@
 /* structs_bug656693.c generated by valac, the Vala compiler
  * generated from structs_bug656693.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/structs/bug657378.c-expected b/tests/structs/bug657378.c-expected
index 2ab07075a3733eb8..25a2e19767bbed59 100644
--- a/tests/structs/bug657378.c-expected
+++ b/tests/structs/bug657378.c-expected
@@ -1,6 +1,13 @@
 /* structs_bug657378.c generated by valac, the Vala compiler
  * generated from structs_bug657378.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/structs/bug658048.c-expected b/tests/structs/bug658048.c-expected
index ad1b358558860d2d..baf8f1e32e73b8d0 100644
--- a/tests/structs/bug658048.c-expected
+++ b/tests/structs/bug658048.c-expected
@@ -1,6 +1,13 @@
 /* structs_bug658048.c generated by valac, the Vala compiler
  * generated from structs_bug658048.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/structs/bug660426.c-expected b/tests/structs/bug660426.c-expected
index 79459ede52f4ccee..2b1ae2bc892a12a1 100644
--- a/tests/structs/bug660426.c-expected
+++ b/tests/structs/bug660426.c-expected
@@ -1,6 +1,13 @@
 /* structs_bug660426.c generated by valac, the Vala compiler
  * generated from structs_bug660426.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/structs/bug661945.c-expected b/tests/structs/bug661945.c-expected
index 5d699a61214ab978..3df485ddd09c1f4c 100644
--- a/tests/structs/bug661945.c-expected
+++ b/tests/structs/bug661945.c-expected
@@ -1,6 +1,13 @@
 /* structs_bug661945.c generated by valac, the Vala compiler
  * generated from structs_bug661945.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/structs/bug667890.c-expected b/tests/structs/bug667890.c-expected
index 958f3df9eedd4313..2f5a4dcff6370039 100644
--- a/tests/structs/bug667890.c-expected
+++ b/tests/structs/bug667890.c-expected
@@ -1,6 +1,13 @@
 /* structs_bug667890.c generated by valac, the Vala compiler
  * generated from structs_bug667890.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/structs/bug669580.c-expected b/tests/structs/bug669580.c-expected
index 1b00223a98c22a64..1ae7c2e73859da71 100644
--- a/tests/structs/bug669580.c-expected
+++ b/tests/structs/bug669580.c-expected
@@ -1,6 +1,13 @@
 /* structs_bug669580.c generated by valac, the Vala compiler
  * generated from structs_bug669580.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/structs/bug685177.c-expected b/tests/structs/bug685177.c-expected
index 501cf7c0ae213863..5f619e4943e19651 100644
--- a/tests/structs/bug685177.c-expected
+++ b/tests/structs/bug685177.c-expected
@@ -1,6 +1,13 @@
 /* structs_bug685177.c generated by valac, the Vala compiler
  * generated from structs_bug685177.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/structs/bug686190.c-expected b/tests/structs/bug686190.c-expected
index 67b25b0c9bda0316..6c255fa6fd7c3008 100644
--- a/tests/structs/bug686190.c-expected
+++ b/tests/structs/bug686190.c-expected
@@ -1,6 +1,13 @@
 /* structs_bug686190.c generated by valac, the Vala compiler
  * generated from structs_bug686190.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/structs/bug688732.c-expected b/tests/structs/bug688732.c-expected
index 74232f52e2a78534..dc9f6b0ab4da51c2 100644
--- a/tests/structs/bug688732.c-expected
+++ b/tests/structs/bug688732.c-expected
@@ -1,6 +1,13 @@
 /* structs_bug688732.c generated by valac, the Vala compiler
  * generated from structs_bug688732.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/structs/bug690380.c-expected b/tests/structs/bug690380.c-expected
index aa4c9f7cef607675..84dc72755694653a 100644
--- a/tests/structs/bug690380.c-expected
+++ b/tests/structs/bug690380.c-expected
@@ -1,6 +1,13 @@
 /* structs_bug690380.c generated by valac, the Vala compiler
  * generated from structs_bug690380.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/structs/bug694140.c-expected b/tests/structs/bug694140.c-expected
index e00332124239ed8b..76b99fb0cd69c61f 100644
--- a/tests/structs/bug694140.c-expected
+++ b/tests/structs/bug694140.c-expected
@@ -1,6 +1,13 @@
 /* structs_bug694140.c generated by valac, the Vala compiler
  * generated from structs_bug694140.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/structs/bug749952.c-expected b/tests/structs/bug749952.c-expected
index b10c074e01ec0289..3a230dd464a48417 100644
--- a/tests/structs/bug749952.c-expected
+++ b/tests/structs/bug749952.c-expected
@@ -1,6 +1,13 @@
 /* structs_bug749952.c generated by valac, the Vala compiler
  * generated from structs_bug749952.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/structs/bug775761.c-expected b/tests/structs/bug775761.c-expected
index 811f8626587fc3b1..788a9b0e7ef0f7f3 100644
--- a/tests/structs/bug775761.c-expected
+++ b/tests/structs/bug775761.c-expected
@@ -1,6 +1,13 @@
 /* structs_bug775761.c generated by valac, the Vala compiler
  * generated from structs_bug775761.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/structs/bug777194-2.c-expected b/tests/structs/bug777194-2.c-expected
index 101c5d55a1268a1c..22c8a39b001d8ec4 100644
--- a/tests/structs/bug777194-2.c-expected
+++ b/tests/structs/bug777194-2.c-expected
@@ -1,6 +1,13 @@
 /* structs_bug777194_2.c generated by valac, the Vala compiler
  * generated from structs_bug777194_2.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/structs/bug777194.c-expected b/tests/structs/bug777194.c-expected
index 055c37c70074d9d7..3d139b1ffb02b6cc 100644
--- a/tests/structs/bug777194.c-expected
+++ b/tests/structs/bug777194.c-expected
@@ -1,6 +1,13 @@
 /* structs_bug777194.c generated by valac, the Vala compiler
  * generated from structs_bug777194.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/structs/cast-struct-boxed.c-expected b/tests/structs/cast-struct-boxed.c-expected
index 23472fd1afc3bfa1..cbc49f170980cf4d 100644
--- a/tests/structs/cast-struct-boxed.c-expected
+++ b/tests/structs/cast-struct-boxed.c-expected
@@ -1,6 +1,13 @@
 /* structs_cast_struct_boxed.c generated by valac, the Vala compiler
  * generated from structs_cast_struct_boxed.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/structs/constructor-params-array.c-expected b/tests/structs/constructor-params-array.c-expected
index d60648f81ff0c74a..bcf05bb7ec404b59 100644
--- a/tests/structs/constructor-params-array.c-expected
+++ b/tests/structs/constructor-params-array.c-expected
@@ -1,6 +1,13 @@
 /* structs_constructor_params_array.c generated by valac, the Vala compiler
  * generated from structs_constructor_params_array.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/structs/constructor-variadic.c-expected b/tests/structs/constructor-variadic.c-expected
index 696f35bba604f697..6dc796de8727b6cc 100644
--- a/tests/structs/constructor-variadic.c-expected
+++ b/tests/structs/constructor-variadic.c-expected
@@ -1,6 +1,13 @@
 /* structs_constructor_variadic.c generated by valac, the Vala compiler
  * generated from structs_constructor_variadic.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/structs/default-gtype.c-expected b/tests/structs/default-gtype.c-expected
index 93efcd45afd99b66..473f91cf97d28d18 100644
--- a/tests/structs/default-gtype.c-expected
+++ b/tests/structs/default-gtype.c-expected
@@ -1,6 +1,13 @@
 /* structs_default_gtype.c generated by valac, the Vala compiler
  * generated from structs_default_gtype.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/structs/gmutex.c-expected b/tests/structs/gmutex.c-expected
index 740fc21683aa375a..1f0c2da049f1fb7e 100644
--- a/tests/structs/gmutex.c-expected
+++ b/tests/structs/gmutex.c-expected
@@ -1,6 +1,13 @@
 /* structs_gmutex.c generated by valac, the Vala compiler
  * generated from structs_gmutex.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <string.h>
 
diff --git a/tests/structs/gtype-base-struct.c-expected b/tests/structs/gtype-base-struct.c-expected
index e5966d7ed7f3c9c4..8663b9fb190b74de 100644
--- a/tests/structs/gtype-base-struct.c-expected
+++ b/tests/structs/gtype-base-struct.c-expected
@@ -1,6 +1,13 @@
 /* structs_gtype_base_struct.c generated by valac, the Vala compiler
  * generated from structs_gtype_base_struct.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <float.h>
 #include <math.h>
diff --git a/tests/structs/gvalue-implicit-comparison.c-expected b/tests/structs/gvalue-implicit-comparison.c-expected
index 21d2e91bbf3e7252..58090f7974f654f7 100644
--- a/tests/structs/gvalue-implicit-comparison.c-expected
+++ b/tests/structs/gvalue-implicit-comparison.c-expected
@@ -1,6 +1,13 @@
 /* structs_gvalue_implicit_comparison.c generated by valac, the Vala compiler
  * generated from structs_gvalue_implicit_comparison.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/structs/gvalue.c-expected b/tests/structs/gvalue.c-expected
index 695fcc1806598ffb..2d8c13cb67c84687 100644
--- a/tests/structs/gvalue.c-expected
+++ b/tests/structs/gvalue.c-expected
@@ -1,6 +1,13 @@
 /* structs_gvalue.c generated by valac, the Vala compiler
  * generated from structs_gvalue.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/structs/namespace-field-nested-initializer.c-expected b/tests/structs/namespace-field-nested-initializer.c-expected
index 8151ab7f6e812e8c..e936b07c8f2c543f 100644
--- a/tests/structs/namespace-field-nested-initializer.c-expected
+++ b/tests/structs/namespace-field-nested-initializer.c-expected
@@ -1,6 +1,13 @@
 /* structs_namespace_field_nested_initializer.c generated by valac, the Vala compiler
  * generated from structs_namespace_field_nested_initializer.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/structs/properties.c-expected b/tests/structs/properties.c-expected
index 16cc2b65417d918a..8a6f05c08582cdcc 100644
--- a/tests/structs/properties.c-expected
+++ b/tests/structs/properties.c-expected
@@ -1,6 +1,13 @@
 /* structs_properties.c generated by valac, the Vala compiler
  * generated from structs_properties.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/structs/simple-type-boxed.c-expected b/tests/structs/simple-type-boxed.c-expected
index 45da6945b29ec231..7014c96670cd673a 100644
--- a/tests/structs/simple-type-boxed.c-expected
+++ b/tests/structs/simple-type-boxed.c-expected
@@ -1,6 +1,13 @@
 /* structs_simple_type_boxed.c generated by valac, the Vala compiler
  * generated from structs_simple_type_boxed.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <string.h>
 
diff --git a/tests/structs/simple-type-constructor.c-expected b/tests/structs/simple-type-constructor.c-expected
index 00a17265ca76ea7a..f64bbd07ab6d42a7 100644
--- a/tests/structs/simple-type-constructor.c-expected
+++ b/tests/structs/simple-type-constructor.c-expected
@@ -1,6 +1,13 @@
 /* structs_simple_type_constructor.c generated by valac, the Vala compiler
  * generated from structs_simple_type_constructor.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/structs/simple-type-default-value.c-expected b/tests/structs/simple-type-default-value.c-expected
index c7bc26b224c211cc..507ffea24adec793 100644
--- a/tests/structs/simple-type-default-value.c-expected
+++ b/tests/structs/simple-type-default-value.c-expected
@@ -1,6 +1,13 @@
 /* structs_simple_type_default_value.c generated by valac, the Vala compiler
  * generated from structs_simple_type_default_value.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/structs/struct-base-types.c-expected b/tests/structs/struct-base-types.c-expected
index 7bbaaf579a657d5e..0f7198d5c606a261 100644
--- a/tests/structs/struct-base-types.c-expected
+++ b/tests/structs/struct-base-types.c-expected
@@ -1,6 +1,13 @@
 /* structs_struct_base_types.c generated by valac, the Vala compiler
  * generated from structs_struct_base_types.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/structs/struct-boxed-cast.c-expected b/tests/structs/struct-boxed-cast.c-expected
index 6b351221aaa3b7f5..6b6706c8ca3f5681 100644
--- a/tests/structs/struct-boxed-cast.c-expected
+++ b/tests/structs/struct-boxed-cast.c-expected
@@ -1,6 +1,13 @@
 /* structs_struct_boxed_cast.c generated by valac, the Vala compiler
  * generated from structs_struct_boxed_cast.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/structs/struct-initializer-list-in-array.c-expected b/tests/structs/struct-initializer-list-in-array.c-expected
index 5158e3d764906117..c430d74c6d292f84 100644
--- a/tests/structs/struct-initializer-list-in-array.c-expected
+++ b/tests/structs/struct-initializer-list-in-array.c-expected
@@ -1,6 +1,13 @@
 /* structs_struct_initializer_list_in_array.c generated by valac, the Vala compiler
  * generated from structs_struct_initializer_list_in_array.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/structs/struct-initializer-list-nested.c-expected b/tests/structs/struct-initializer-list-nested.c-expected
index 441dd9ab16212eec..2df9f4a03592fddd 100644
--- a/tests/structs/struct-initializer-list-nested.c-expected
+++ b/tests/structs/struct-initializer-list-nested.c-expected
@@ -1,6 +1,13 @@
 /* structs_struct_initializer_list_nested.c generated by valac, the Vala compiler
  * generated from structs_struct_initializer_list_nested.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/structs/struct-no-gtype-inherit.c-expected b/tests/structs/struct-no-gtype-inherit.c-expected
index 99211b9f3a928c97..08915797e6ba5698 100644
--- a/tests/structs/struct-no-gtype-inherit.c-expected
+++ b/tests/structs/struct-no-gtype-inherit.c-expected
@@ -1,6 +1,13 @@
 /* structs_struct_no_gtype_inherit.c generated by valac, the Vala compiler
  * generated from structs_struct_no_gtype_inherit.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <stdint.h>
 
 typedef int32_t foo_t;
diff --git a/tests/structs/struct-no-gtype.c-expected b/tests/structs/struct-no-gtype.c-expected
index b12fb74fcd881929..b97ae863ddb5412d 100644
--- a/tests/structs/struct-no-gtype.c-expected
+++ b/tests/structs/struct-no-gtype.c-expected
@@ -1,6 +1,13 @@
 /* structs_struct_no_gtype.c generated by valac, the Vala compiler
  * generated from structs_struct_no_gtype.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <string.h>
 
diff --git a/tests/structs/struct-static-field-initializer-3.c-expected b/tests/structs/struct-static-field-initializer-3.c-expected
index e0241e830fa98b2b..287e7a9331c8b115 100644
--- a/tests/structs/struct-static-field-initializer-3.c-expected
+++ b/tests/structs/struct-static-field-initializer-3.c-expected
@@ -1,6 +1,13 @@
 /* structs_struct_static_field_initializer_3.c generated by valac, the Vala compiler
  * generated from structs_struct_static_field_initializer_3.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/structs/struct-static-field-initializer.c-expected b/tests/structs/struct-static-field-initializer.c-expected
index 6c6c164705b765f5..4d2ae563fec6bbf3 100644
--- a/tests/structs/struct-static-field-initializer.c-expected
+++ b/tests/structs/struct-static-field-initializer.c-expected
@@ -1,6 +1,13 @@
 /* structs_struct_static_field_initializer.c generated by valac, the Vala compiler
  * generated from structs_struct_static_field_initializer.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/structs/struct_only.c-expected b/tests/structs/struct_only.c-expected
index fe1b35e0b0817a59..4a297b4d0763a18f 100644
--- a/tests/structs/struct_only.c-expected
+++ b/tests/structs/struct_only.c-expected
@@ -1,6 +1,13 @@
 /* structs_struct_only.c generated by valac, the Vala compiler
  * generated from structs_struct_only.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/structs/structs.c-expected b/tests/structs/structs.c-expected
index 4fba50587fa8e821..fd59eefb696fe74e 100644
--- a/tests/structs/structs.c-expected
+++ b/tests/structs/structs.c-expected
@@ -1,6 +1,13 @@
 /* structs_structs.c generated by valac, the Vala compiler
  * generated from structs_structs.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/threads/threadpool.c-expected b/tests/threads/threadpool.c-expected
index 0ff74363f9e6f083..573c7e531e4f101f 100644
--- a/tests/threads/threadpool.c-expected
+++ b/tests/threads/threadpool.c-expected
@@ -1,6 +1,13 @@
 /* threads_threadpool.c generated by valac, the Vala compiler
  * generated from threads_threadpool.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#pragma GCC diagnostic warning "-Wint-conversion"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>