diff --git a/lib/wrapper-end.js b/lib/wrapper-end.js
index 3d1fcc4c..12b771d9 100644
--- a/lib/wrapper-end.js
+++ b/lib/wrapper-end.js
@@ -7,6 +7,8 @@ var doPolyfill = typeof Promise === 'undefined';
 if (typeof document !== 'undefined') {
   var scripts = document.getElementsByTagName('script');
   $__curScript = scripts[scripts.length - 1];
+  if ($__curScript.defer || $__curScript.async)
+    $__curScript = document.currentScript;
   if (doPolyfill) {
     var curPath = $__curScript.src;
     var basePath = curPath.substr(0, curPath.lastIndexOf('/') + 1);