diff --git a/package.json b/package.json
index 1678703..5ffd585 100644
--- a/package.json
+++ b/package.json
@@ -39,6 +39,6 @@
   "devDependencies": {
     "chai": "^4.1.0",
     "istanbul": "^0.4.2",
-    "mocha": "^3.2.0"
+    "mocha": "^4.0.0"
   }
 }