diff -rupN --no-dereference freetype-2.13.2/include/freetype/ftoutln.h freetype-2.13.2-new/include/freetype/ftoutln.h
--- freetype-2.13.2/include/freetype/ftoutln.h	2023-04-30 16:42:51.000000000 +0200
+++ freetype-2.13.2-new/include/freetype/ftoutln.h	2024-01-17 10:34:17.037246539 +0100
@@ -166,6 +166,15 @@ FT_BEGIN_HEADER
                   FT_Int       numContours,
                   FT_Outline  *anoutline );
 
+  /*
+   * Kept downstream for ABI compatibility only.
+   * It just throws error now. Remove once soname has been bumped.
+   */
+  FT_EXPORT( FT_Error )
+  FT_Outline_New_Internal( FT_Memory    memory,
+                           FT_UInt      numPoints,
+                           FT_Int       numContours,
+                           FT_Outline  *anoutline );
 
   /**************************************************************************
    *
@@ -193,6 +202,13 @@ FT_BEGIN_HEADER
   FT_Outline_Done( FT_Library   library,
                    FT_Outline*  outline );
 
+  /*
+   * Kept downstream for ABI compatibility only.
+   * It just throws error now. Remove once soname has been bumped.
+   */
+  FT_EXPORT( FT_Error )
+  FT_Outline_Done_Internal( FT_Memory    memory,
+                            FT_Outline*  outline );
 
   /**************************************************************************
    *
diff -rupN --no-dereference freetype-2.13.2/src/base/ftoutln.c freetype-2.13.2-new/src/base/ftoutln.c
--- freetype-2.13.2/src/base/ftoutln.c	2023-02-27 06:39:44.000000000 +0100
+++ freetype-2.13.2-new/src/base/ftoutln.c	2024-01-17 10:34:17.041246532 +0100
@@ -300,6 +300,19 @@
 
   /* documentation is in ftoutln.h */
 
+  /*
+   * Kept downstream for ABI compatibility only.
+   * It just throws error now. Remove once soname has been bumped.
+   */
+  FT_EXPORT_DEF( FT_Error )
+  FT_Outline_New_Internal( FT_Memory    memory,
+                           FT_UInt      numPoints,
+                           FT_Int       numContours,
+                           FT_Outline  *anoutline )
+  {
+    return FT_THROW( Unimplemented_Feature );
+  }
+
   FT_EXPORT_DEF( FT_Error )
   FT_Outline_New( FT_Library   library,
                   FT_UInt      numPoints,
@@ -432,6 +445,17 @@
 
   /* documentation is in ftoutln.h */
 
+  /*
+   * Kept downstream for ABI compatibility only.
+   * It just throws error now. Remove once soname has been bumped.
+   */
+  FT_EXPORT_DEF( FT_Error )
+  FT_Outline_Done_Internal( FT_Memory    memory,
+                            FT_Outline*  outline )
+  {
+    return FT_THROW( Unimplemented_Feature );
+  }
+
   FT_EXPORT_DEF( FT_Error )
   FT_Outline_Done( FT_Library   library,
                    FT_Outline*  outline )