diff --git a/package.json b/package.json
index 438405b..2350e41 100644
--- a/package.json
+++ b/package.json
@@ -27,6 +27,7 @@
   "devDependencies": {
     "chai": "^3.5.0",
     "chalk": "^1.1.3",
+    "del": "^2.2.2",
     "gulp": "^3.9.1",
     "gulp-bump": "^2.5.1",
     "gulp-coverage": "^0.3.38",