diff --git a/package.json b/package.json
index 1ab4ea0..0d979a9 100644
--- a/package.json
+++ b/package.json
@@ -32,7 +32,7 @@
     "socket.io-client": "^1.4.8"
   },
   "devDependencies": {
-    "chai": "^3.5.0",
+    "chai": "^4.1.2",
     "mocha": "^2.5.3"
   }
 }