diff --git a/common/rfb/VNCServerST.h b/common/rfb/VNCServerST.h
index 584c48c..9a1a44d 100644
--- a/common/rfb/VNCServerST.h
+++ b/common/rfb/VNCServerST.h
@@ -227,6 +227,7 @@
     bool needRenderedCursor();
     void startFrameClock();
     void stopFrameClock();
+    int msToNextUpdate();
     void writeUpdate();
     bool checkUpdate();
     const RenderedCursor* getRenderedCursor();