diff --git a/Gruntfile.js b/Gruntfile.js
index 3b2adea2a01..4f970bd97c2 100644
--- a/Gruntfile.js
+++ b/Gruntfile.js
@@ -218,8 +218,10 @@ module.exports = function(grunt) {
       var messages = grunt.file.readJSON(abspath);
 
       for (var key in messages){
-        if (en[key].placeholders !== undefined && messages[key].placeholders === undefined){
-          messages[key].placeholders = en[key].placeholders;
+        if (en[key] !== undefined && messages[key] !== undefined){
+          if (en[key].placeholders !== undefined && messages[key].placeholders === undefined){
+            messages[key].placeholders = en[key].placeholders;
+          }
         }
       }