diff --git a/package.json b/package.json
index b08a735..97d2a41 100644
--- a/package.json
+++ b/package.json
@@ -34,7 +34,7 @@
     "fuse.js": "^3.0.0"
   },
   "devDependencies": {
-    "chai": "^3.5.0",
+    "chai": "^4.0.2",
     "codeclimate-test-reporter": "^0.4.1",
     "coveralls": "^2.13.0",
     "eslint": "^3.19.0",