diff --git a/src/Main/options.cxx b/src/Main/options.cxx
index 8ed6affd8..e94ed4f6c 100644
--- a/src/Main/options.cxx
+++ b/src/Main/options.cxx
@@ -881,7 +881,7 @@ fgSetupProxy( const char *arg )
 {
     string options = arg;
     string host, port, auth;
-    unsigned int pos;
+    string::size_type pos;
 
     host = port = auth = "";
     if ((pos = options.find("@")) != string::npos)