diff --git a/package.json b/package.json
index 047d457..8fdd821 100644
--- a/package.json
+++ b/package.json
@@ -17,6 +17,7 @@
   "license": "MIT",
   "devDependencies": {
     "browserify": "^9.0.8",
+    "chai": "^2.2.0",
     "grunt": "^0.4.5",
     "grunt-babel": "^5.0.0",
     "grunt-browserify": "^3.7.0",