@@ -27,10 +27,11 @@
 /*!
  * @class OFDate OFDate.h ObjFW/OFDate.h
  *
  * @brief A class for storing, accessing and comparing dates.
  */
+OF_SUBCLASSING_RESTRICTED
 @interface OFDate: OFObject <OFCopying, OFComparing, OFSerialization,
     OFMessagePackRepresentation>
 {
 	of_time_interval_t _seconds;
 }