diff --git a/tools/winegcc/winegcc.c b/tools/winegcc/winegcc.c
index 113819d26cc..40dacf8fdde 100644
--- a/tools/winegcc/winegcc.c
+++ b/tools/winegcc/winegcc.c
@@ -287,7 +287,14 @@ static void compile(struct options* opts, const char* lang)
 
     if (gcc_defs)
     {
-#ifdef __APPLE__ /* Mac OS X uses a 16-byte aligned stack and not a 4-byte one */
+#ifdef __x86_64__
+        strarray_add(comp_args, "-D__stdcall=__attribute__((ms_abi))");
+        strarray_add(comp_args, "-D__cdecl=__attribute__((ms_abi))");
+        strarray_add(comp_args, "-D_stdcall=__attribute__((ms_abi))");
+        strarray_add(comp_args, "-D_cdecl=__attribute__((ms_abi))");
+        strarray_add(comp_args, "-D__fastcall=__attribute__((ms_abi))");
+        strarray_add(comp_args, "-D_fastcall=__attribute__((ms_abi))");
+#elif defined(__APPLE__) /* Mac OS X uses a 16-byte aligned stack and not a 4-byte one */
 	strarray_add(comp_args, "-D__stdcall=__attribute__((__stdcall__)) __attribute__((__force_align_arg_pointer__))");
 	strarray_add(comp_args, "-D__cdecl=__attribute__((__cdecl__)) __attribute__((__force_align_arg_pointer__))");
 	strarray_add(comp_args, "-D_stdcall=__attribute__((__stdcall__)) __attribute__((__force_align_arg_pointer__))");