diff --git a/package.json b/package.json
index 77ecc09..257e84c 100644
--- a/package.json
+++ b/package.json
@@ -34,6 +34,7 @@
     "babel-eslint": "^7.1.0",
     "babel-preset-es2015": "^6.18.0",
     "babel-preset-stage-0": "^6.16.0",
+    "chai": "^3.5.0",
     "eslint": "^3.10.1",
     "mocha": "^3.1.2",
     "rimraf": "^2.5.4",