diff --git a/package.json b/package.json
index 8d33849..0f83400 100644
--- a/package.json
+++ b/package.json
@@ -28,7 +28,7 @@
   "devDependencies": {
     "browserify": "^14.0.0",
     "expect.js": "^0.3.1",
-    "mocha": "^3.0.2"
+    "mocha": "^4.0.0"
   },
   "dependencies": {
     "is-plain-object": "^2.0.1"