diff --git a/common/rfb/CMsgWriterV3.h b/common/rfb/CMsgWriterV3.h
index 0b2f9af..15c6d6d 100644
--- a/common/rfb/CMsgWriterV3.h
+++ b/common/rfb/CMsgWriterV3.h
@@ -30,6 +30,8 @@
     virtual void startMsg(int type);
     virtual void endMsg();
 
+    virtual void writeSetDesktopSize(int width, int height,
+                                     const ScreenSet& layout);
   };
 }
 #endif