diff --git a/package.json b/package.json
index c771708..c40f060 100644
--- a/package.json
+++ b/package.json
@@ -28,6 +28,6 @@
   },
   "devDependencies": {
     "chai": "^3.0.0",
-    "mocha": "*"
+    "mocha": "3.4.2"
   }
 }