diff --git a/package.json b/package.json
index e6a9997..0b8abc1 100644
--- a/package.json
+++ b/package.json
@@ -27,7 +27,7 @@
     "test": "script/test"
   },
   "devDependencies": {
-    "mocha": "*",
+    "mocha": "2.5.0",
     "chai": "*",
     "sinon-chai": "*",
     "sinon": "*",