diff --git a/package.json b/package.json
index 91a8124..2c687f7 100644
--- a/package.json
+++ b/package.json
@@ -32,7 +32,7 @@
     "babel-plugin-add-module-exports": "^0.2.1",
     "babel-preset-latest": "^6.16.0",
     "babel-register": "^6.18.0",
-    "chai": "^3.5.0",
+    "chai": "4.3.4",
     "eslint": "^3.13.1",
     "eslint-loader": "^1.6.1",
     "mocha": "^3.2.0",