diff --git a/package.json b/package.json
index 7d1a7b8..75ab622 100644
--- a/package.json
+++ b/package.json
@@ -37,7 +37,7 @@
     "babel-eslint": "*",
     "eslint": "1.10.3",
     "eslint-config-airbnb": "4.0.0",
-    "chai": "3.5.0",
+    "chai": "4.0.1",
     "mocha": "3.1.2",
     "sinon": "1.17.4",
     "sinon-chai": "2.8.0"