diff --git a/testsuite/libffi.call/closure_thiscall.c b/testsuite/libffi.call/closure_thiscall.c
index 12a0a637..8f7d2fae 100644
--- a/testsuite/libffi.call/closure_thiscall.c
+++ b/testsuite/libffi.call/closure_thiscall.c
@@ -23,10 +23,7 @@ closure_test_thiscall(ffi_cif* cif __UNUSED__, void* resp, void** args,
 
 }
 
-#ifndef _MSC_VER
-#define __thiscall __attribute__((thiscall))
-#endif
-typedef int (__thiscall *closure_test_type0)(int, int, int, int);
+typedef int (__THISCALL__ *closure_test_type0)(int, int, int, int);
 
 int main (void)
 {
diff --git a/testsuite/libffi.call/ffitest.h b/testsuite/libffi.call/ffitest.h
index 2fc25357..19193758 100644
--- a/testsuite/libffi.call/ffitest.h
+++ b/testsuite/libffi.call/ffitest.h
@@ -22,10 +22,12 @@
 #if defined(__GNUC__)
 #define __UNUSED__ __attribute__((__unused__))
 #define __STDCALL__ __attribute__((stdcall))
+#define __THISCALL__ __attribute__((thiscall))
 #define __FASTCALL__ __attribute__((fastcall))
 #else
 #define __UNUSED__
 #define __STDCALL__ __stdcall
+#define __THISCALL__ __thiscall
 #define __FASTCALL__ __fastcall
 #endif