diff --git a/package.json b/package.json
index b155b1d..33433a0 100644
--- a/package.json
+++ b/package.json
@@ -20,7 +20,7 @@
   },
   "devDependencies": {
     "chai": "4.1.2",
-    "coffeescript": "1.12.7",
+    "coffeescript": "2.2.4",
     "mocha": "5.0.4"
   },
   "keywords": [