diff --git a/pkgs/by-name/mo/molden/package.nix b/pkgs/by-name/mo/molden/package.nix
index 0d46797fc0b1..7ca292390b95 100644
--- a/pkgs/by-name/mo/molden/package.nix
+++ b/pkgs/by-name/mo/molden/package.nix
@@ -27,6 +27,9 @@ stdenv.mkDerivation rec {
 
   patches = [ ./dont_register_file_types.patch ];
 
+  # fix build with GCC 14
+  env.NIX_CFLAGS_COMPILE = "-Wno-implicit-function-declaration -Wno-implicit-int -Wno-return-mismatch";
+
   postPatch = ''
     substituteInPlace ./makefile --replace '-L/usr/X11R6/lib'  "" \
                                  --replace '-I/usr/X11R6/include' "" \