diff --git a/libcxx/test/support/is_niebloid.h b/libcxx/test/support/is_niebloid.h
--- a/libcxx/test/support/is_niebloid.h
+++ b/libcxx/test/support/is_niebloid.h
@@ -31,7 +31,7 @@
   static_assert(!std::assignable_from<X&, X const>);
   static_assert(!std::assignable_from<X&, X&>);
   static_assert(!std::assignable_from<X&, X const&>);
-  static_assert(std::is_final_v<X>);
+  LIBCPP_STATIC_ASSERT(std::is_final_v<X>);
   return true;
 }
 #endif