diff --git a/clang/lib/Headers/fxsrintrin.h b/clang/lib/Headers/fxsrintrin.h
index d7fd39bd6b65..2dc13f78c465 100644
--- a/clang/lib/Headers/fxsrintrin.h
+++ b/clang/lib/Headers/fxsrintrin.h
@@ -50,4 +50,6 @@ _fxrstor64(void *__p) {
   return __builtin_ia32_fxrstor64(__p);
 }
 
+#undef DEFAULT_FN_ATTRS
+
 #endif