@@ -831,10 +831,15 @@
 
 	old_OBJCFLAGS="$OBJCFLAGS"
 	OBJCFLAGS="$OBJCFLAGS -Wcast-align"
 	AC_MSG_CHECKING(whether -Wcast-align is buggy)
 	AC_TRY_COMPILE([
+		#ifdef __has_attribute
+		# if __has_attribute(objc_root_class)
+		__attribute__((objc_root_class))
+		# endif
+		#endif
 		@interface Foo
 		{
 			struct objc_class *_isa;
 		}
 		@end