diff --git a/package.json b/package.json
index 4976360..c8c8642 100644
--- a/package.json
+++ b/package.json
@@ -33,7 +33,7 @@
     "babel-cli": "6.24.1",
     "babel-plugin-add-module-exports": "0.2.1",
     "babel-preset-es2015": "6.24.1",
-    "chai": "3.5.0",
+    "chai": "4.0.1",
     "coveralls": "2.13.1",
     "cz-conventional-changelog": "1.2.0",
     "isparta": "4.0.0",