diff --git a/package.json b/package.json
index e0379b9..fd0a239 100644
--- a/package.json
+++ b/package.json
@@ -21,6 +21,7 @@
   },
   "homepage": "https://gitlab.com/mmk2410/rangitaki#README",
   "devDependencies": {
+    "coffee-script": "^1.10.0",
     "del": "^2.2.0",
     "gulp": "^3.9.1",
     "gulp-coffee": "^2.3.2",