@@ -114,11 +114,13 @@
 /*!
  * @class OFNumber OFNumber.h ObjFW/OFNumber.h
  *
  * @brief Provides a way to store a number in an object.
  */
+#ifndef OF_NUMBER_M
 OF_SUBCLASSING_RESTRICTED
+#endif
 @interface OFNumber: OFValue <OFComparing, OFSerialization,
     OFJSONRepresentation, OFMessagePackRepresentation>
 {
 	union of_number_value {
 		bool		   bool_;