@@ -676,11 +676,11 @@
 - (OFXMLElement *)XMLElementBySerializing
 {
 	void *pool = objc_autoreleasePoolPush();
 	OFXMLElement *element;
 	OFEnumerator *keyEnumerator, *objectEnumerator;
-	id key, object;
+	id <OFSerialization> key, object;
 
 	if ([self isKindOfClass: [OFMutableDictionary class]])
 		element = [OFXMLElement elementWithName: @"OFMutableDictionary"
 					      namespace: OF_SERIALIZATION_NS];
 	else