diff --git a/package.json b/package.json
index 3726cf7..e732661 100644
--- a/package.json
+++ b/package.json
@@ -11,7 +11,7 @@
   "devDependencies": {
     "bluebird": "2",
     "istanbul": "0",
-    "mocha": "2"
+    "mocha": "2.4.1"
   },
   "scripts": {
     "test": "mocha --reporter spec",