@@ -30,13 +30,14 @@
 
 #import "OFKernelEventObserver.h"
 
 OF_ASSUME_NONNULL_BEGIN
 
+OF_SUBCLASSING_RESTRICTED
 @interface OFSelectKernelEventObserver: OFKernelEventObserver
 {
 	fd_set _readFDs, _writeFDs;
 	int _maxFD;
 }
 @end
 
 OF_ASSUME_NONNULL_END