--- a/runtime.c
+++ b/runtime.c
@@ -111,7 +111,7 @@
 #endif
 
 #ifdef C_HACKED_APPLY
-# if defined(__MACH__) || defined(__MINGW32__) || defined(__CYGWIN__)
+# if defined(__MINGW32__) || defined(__CYGWIN__)
 extern void C_do_apply_hack(void *proc, C_word *args, int count) C_noret;
 # else
 extern void _C_do_apply_hack(void *proc, C_word *args, int count) C_noret;