diff --git a/package.json b/package.json
index d398cf8..9c29a13 100644
--- a/package.json
+++ b/package.json
@@ -28,7 +28,7 @@
   "devDependencies": {
     "babel-core": "^6.0.12",
     "babel-preset-es2015": "^6.0.12",
-    "chai": "^3.0.0",
+    "chai": "^4.0.1",
     "coveralls": "^2.11.2",
     "del": "^2.0.0",
     "eslint-config-dustinspecker": "^1.1.0",