diff --git a/Source/cmSystemTools.cxx b/Source/cmSystemTools.cxx
index 88f96d1bc..f953b7105 100644
--- a/Source/cmSystemTools.cxx
+++ b/Source/cmSystemTools.cxx
@@ -2000,6 +2000,7 @@ int copy_data(struct archive *ar, struct archive *aw)
       return (r);
       }
     }
+  return r;
 }
 
 bool extract_tar(const char* outFileName, bool verbose,