diff --git a/Source/cmFileCommand.cxx b/Source/cmFileCommand.cxx
index 539ed0fc9..8260cc74e 100644
--- a/Source/cmFileCommand.cxx
+++ b/Source/cmFileCommand.cxx
@@ -2510,6 +2510,9 @@ namespace{
     cURLProgressHelper *helper =
       reinterpret_cast<cURLProgressHelper *>(clientp);
 
+    static_cast<void>(ultotal);
+    static_cast<void>(ulnow);
+
     std::string status;
     if (helper->UpdatePercentage(dlnow, dltotal, status))
       {