@@ -44,10 +44,11 @@
 /*!
  * @class OFProcess OFProcess.h ObjFW/OFProcess.h
  *
  * @brief A class for stream-like communication with a newly created process.
  */
+OF_SUBCLASSING_RESTRICTED
 @interface OFProcess: OFStream
 #ifndef OF_WINDOWS
     <OFReadyForReadingObserving, OFReadyForWritingObserving>
 #endif
 {