diff --git a/public/icvar.h b/public/icvar.h
index 7a9b066c..ffb795bd 100644
--- a/public/icvar.h
+++ b/public/icvar.h
@@ -62,7 +62,7 @@ public:
 	virtual CVarDLLIdentifier_t AllocateDLLIdentifier() = 0;
 
 	// Register, unregister commands
-	virtual void			RegisterConCommand( ConCommandBase *pCommandBase ) = 0;
+	virtual void			RegisterConCommand( ConCommandBase *pCommandBase, bool unknown=true ) = 0;
 	virtual void			UnregisterConCommand( ConCommandBase *pCommandBase ) = 0;
 	virtual void			UnregisterConCommands( CVarDLLIdentifier_t id ) = 0;