diff --git a/package.json b/package.json
index 5112aab..54ca922 100644
--- a/package.json
+++ b/package.json
@@ -11,7 +11,7 @@
   "devDependencies": {
     "babel-preset-es2015": "^6.24.1",
     "grunt-babel": "^7.0.0",
-    "grunt-contrib-concat": "^0.5.0",
+    "grunt-contrib-concat": "^2.1.0",
     "grunt-contrib-cssmin": "^0.10.0",
     "grunt-contrib-uglify-es": "^3.3.0"
   }