@@ -342,11 +342,11 @@
 #endif
 
 	if (self != [OFDate class])
 		return;
 
-	placeholder.isa = [OFDatePlaceholder class];
+	object_setClass((id)&placeholder, [OFDatePlaceholder class]);
 
 #if (!defined(HAVE_GMTIME_R) || !defined(HAVE_LOCALTIME_R)) && \
     defined(OF_HAVE_THREADS)
 	mutex = [[OFMutex alloc] init];
 	atexit(releaseMutex);