diff --git a/package.json b/package.json
index 1e84516..6d94596 100644
--- a/package.json
+++ b/package.json
@@ -51,7 +51,7 @@
   },
   "devDependencies": {
     "bluebird": "2",
-    "mocha": "2",
+    "mocha": "2.4.1",
     "istanbul": "0"
   },
   "scripts": {