diff --git a/package.json b/package.json
index 34168ae..fd8ab99 100644
--- a/package.json
+++ b/package.json
@@ -14,7 +14,7 @@
     "mocha": "~3.3.0",
     "sinon": "~1.17.6",
     "sinon-chai": "~2.8.0",
-    "chai": "~3.5.0",
+    "chai": "~4.0.0",
     "request": "~2.80.0"
   },
   "scripts": {