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);
 
diff --git a/vncviewer/CConn.h b/vncviewer/CConn.h
index 709ca2f..1b92937 100644
--- a/vncviewer/CConn.h
+++ b/vncviewer/CConn.h
@@ -51,8 +51,8 @@
   void serverInit();
 
   void setDesktopSize(int w, int h);
-  void setExtendedDesktopSize(int reason, int result, int w, int h,
-                              const rfb::ScreenSet& layout);
+  void setExtendedDesktopSize(unsigned reason, unsigned result,
+                              int w, int h, const rfb::ScreenSet& layout);
 
   void setName(const char* name);