diff --git a/tasks/build.js b/tasks/build.js
index 5a8c918..d76ccfc 100644
--- a/tasks/build.js
+++ b/tasks/build.js
@@ -19,7 +19,8 @@ module.exports = function(grunt) {
         dest: "build/"
       },
       vendorjs: {
-        src: [ "es6-shim/es6-shim.min.js" ],
+        src: ["es6-shim/es6-shim.min.js",
+          "es6-shim/es6-shim.map"],
         expand: true,
         cwd: "bower_components/",
         dest: "build/vendor/"