diff --git a/github.js b/github.js
index 05f44259..bc87af50 100644
--- a/github.js
+++ b/github.js
@@ -63,7 +63,8 @@
                }
             }
 
-            return url + (typeof window !== 'undefined' ? '&' + new Date().getTime() : '');
+            return url.replace(/(&timestamp=\d+)/, '') +
+               (typeof window !== 'undefined' ? '&timestamp=' + new Date().getTime() : '');
          }
 
          var xhr = new XMLHttpRequest();