diff --git a/tools/build-plugins/protect.js b/tools/build-plugins/protect.js
index b0b5f1de99..13662968b4 100644
--- a/tools/build-plugins/protect.js
+++ b/tools/build-plugins/protect.js
@@ -8,6 +8,7 @@ module.exports = function (babel) {
       Program: function (node, parent, scope, file) {
         if (file.opts.filename.indexOf("tools/protect") >= 0) return;
         if (file.opts.filename.indexOf("templates") >= 0) return;
+        if (file.opts.filename.indexOf("polyfill") >= 0) return;
 
         var from = "/" + path.dirname(file.opts.filename.replace(/^src/, "lib"));
         var to   = "/lib/babel/tools";