diff --git a/vncviewer/CConn.cxx b/vncviewer/CConn.cxx
index 5935c17..ab5c9cc 100644
--- a/vncviewer/CConn.cxx
+++ b/vncviewer/CConn.cxx
@@ -313,8 +313,8 @@
 }
 
 // setExtendedDesktopSize() is a more advanced version of setDesktopSize()
-void CConn::setExtendedDesktopSize(int reason, int result, int w, int h,
-                                   const rfb::ScreenSet& layout)
+void CConn::setExtendedDesktopSize(unsigned reason, unsigned result,
+                                   int w, int h, const rfb::ScreenSet& layout)
 {
   CConnection::setExtendedDesktopSize(reason, result, w, h, layout);