diff --git a/package.json b/package.json
index 3d84971..b6af0c8 100644
--- a/package.json
+++ b/package.json
@@ -35,7 +35,7 @@
     "eslint": "3.0.1"
   },
   "devDependencies": {
-    "chai": "3.5.0",
+    "chai": "4.0.1",
     "conventional-changelog-cli": "1.2.0",
     "conventional-github-releaser": "1.1.3",
     "mocha": "2.5.3",