diff --git a/unix/vncviewer/CConn.h b/unix/vncviewer/CConn.h
index 96a76fe..3bf0a82 100644
--- a/unix/vncviewer/CConn.h
+++ b/unix/vncviewer/CConn.h
@@ -81,6 +81,7 @@
   void setColourMapEntries(int firstColour, int nColours, rdr::U16* rgbs);
   void bell();
   void serverCutText(const char* str, int len);
+  void framebufferUpdateStart();
   void framebufferUpdateEnd();
   void beginRect(const rfb::Rect& r, unsigned int encoding);
   void endRect(const rfb::Rect& r, unsigned int encoding);