diff --git a/common/rfb/VNCSConnectionST.cxx b/common/rfb/VNCSConnectionST.cxx
index 126fb4e..f22b993 100644
--- a/common/rfb/VNCSConnectionST.cxx
+++ b/common/rfb/VNCSConnectionST.cxx
@@ -883,7 +883,7 @@
 
 bool VNCSConnectionST::isCongested()
 {
-  unsigned eta;
+  int eta;
 
   congestionTimer.stop();