diff --git a/package.json b/package.json
index 30b2eec..eaddf51 100644
--- a/package.json
+++ b/package.json
@@ -21,6 +21,7 @@
   "devDependencies": {
     "grunt": "^0.4.5",
     "grunt-contrib-concat": "^0.5.1",
+    "grunt-contrib-clean": "0.6.0",
     "grunt-contrib-uglify": "^0.9.1"
   }
 }