diff --git a/package.json b/package.json
index 6a61493..1c17b3b 100644
--- a/package.json
+++ b/package.json
@@ -51,7 +51,7 @@
     "autoprefixer": "^7.0.1",
     "babel-plugin-external-helpers": "^6.22.0",
     "babel-preset-es2015": "^6.24.1",
-    "chai": "^3.5.0",
+    "chai": "^4.0.1",
     "chai-dom": "^1.4.0",
     "es6-promise": "^4.0.5",
     "eslint": "^3.19.0",