@@ -19,12 +19,13 @@
 
 OF_ASSUME_NONNULL_BEGIN
 
 @class OFMapTable;
 
+OF_SUBCLASSING_RESTRICTED
 @interface OFMutableMapTableDictionary: OFMutableDictionary
 {
 	OFMapTable *_mapTable;
 }
 @end
 
 OF_ASSUME_NONNULL_END