@@ -42,11 +42,11 @@
 };
 
 /**
  * \brief Provides a way to store a number in an object.
  */
-@interface OFNumber: OFObject
+@interface OFNumber: OFObject <OFCopying>
 {
 	union {
 		char	       char_;
 		short	       short_;
 		int	       int_;