--- a/client/gruntfile.js	Thu Sep 10 00:35:59 2015 +0200
+++ b/client/gruntfile.js	Thu Sep 10 01:01:58 2015 +0200
@@ -178,11 +178,16 @@
                 eqeqeq: true,
                 eqnull: true,
                 browser: true,
+                esnext: true,
                 globals: {
                     jQuery: true
                 },
             },
-            all: ['Gruntfile.js', 'js/**/*.js', 'data/simple-persist.js']
+            all: [
+                'Gruntfile.js',
+                'js/**/*.js',
+                'data/simple-persist.js'
+            ]
         },
         bower: {
             install: {