diff --git a/SystemInformation.cxx b/SystemInformation.cxx
index 54a1da854cb6b2a2bb11c8977c0a64e2f681444a..7239a24f21c8b209a5478fb6850f531c0677130b 100644
--- a/SystemInformation.cxx
+++ b/SystemInformation.cxx
@@ -2852,7 +2852,7 @@ kwsys_stl::string SystemInformationImplementation::ParseValueFromKStat(const cha
   kwsys_stl::string buffer = this->RunProcess(args);
 
   kwsys_stl::string value = "";
-  for(unsigned int i=buffer.size()-1;i>0;i--)
+  for(size_t i=buffer.size()-1;i>0;i--)
     {
     if(buffer[i] == ' ' || buffer[i] == '\t')
       {