diff --git a/package.json b/package.json
index cb42322..d229ba5 100644
--- a/package.json
+++ b/package.json
@@ -16,7 +16,7 @@
     "twilio": "~3.17.1"
   },
   "devDependencies": {
-    "chai": "^3.5.0",
+    "chai": "^4.3.8",
     "cheerio": "^0.22.0",
     "mocha": "^3.1.0",
     "supertest": "^2.0.0"