diff --git a/package.json b/package.json
index 7ce39de..afbb2ed 100644
--- a/package.json
+++ b/package.json
@@ -8,7 +8,7 @@
     "lodash": "~2.4.1"
   },
   "devDependencies": {
-    "chai": "~1.9.0",
+    "chai": "~4.3.1",
     "mocha": "~1.17.1"
   }
 }