diff --git a/80a9ab41b91ab849794bb7830f0a98d862c08269.diff b/80a9ab41b91ab849794bb7830f0a98d862c08269.diff
deleted file mode 100644
index c05c376..0000000
--- a/80a9ab41b91ab849794bb7830f0a98d862c08269.diff
+++ /dev/null
@@ -1,13 +0,0 @@
-diff --git a/src/solver/modwrap.c b/src/solver/modwrap.c
-index a180dba649632c3d9c8d7e812a4bac3a60177d2d..124d4bc4b7b3b313f34deb223afc6267451bf974 100644
---- a/src/solver/modwrap.c
-+++ b/src/solver/modwrap.c
-@@ -18,6 +18,6 @@ char *solve_equation(const char *eq)
-         solve_equation_closure = caml_named_value("solve_equation");
-     }
- 
--    value v = copy_string(eq);
--    return strdup(String_val(callback(*solve_equation_closure, v)));
-+    value v = caml_copy_string(eq);
-+    return strdup(String_val(caml_callback(*solve_equation_closure, v)));
- }
diff --git a/kalzium.spec b/kalzium.spec
index 5d4cb29..332c57c 100644
--- a/kalzium.spec
+++ b/kalzium.spec
@@ -31,7 +31,6 @@ URL:     https://edu.kde.org/kalzium/
 Source0: http://download.kde.org/%{stable}/release-service/%{version}/src/%{name}-%{version}.tar.xz
 
 ## upstream patches
-Patch0: 80a9ab41b91ab849794bb7830f0a98d862c08269.diff
 
 %if ! 0%{?bootstrap}
 BuildRequires: libappstream-glib