diff --git a/common/rfb/TightEncoder.cxx b/common/rfb/TightEncoder.cxx
index ec19c2e..fe2470b 100644
--- a/common/rfb/TightEncoder.cxx
+++ b/common/rfb/TightEncoder.cxx
@@ -201,7 +201,7 @@
   }
 
   while (count) {
-    int iter_count;
+    unsigned int iter_count;
 
     iter_count = sizeof(rgb)/3;
     if (iter_count > count)