diff --git a/package.json b/package.json
index 8977188..aa1e73c 100644
--- a/package.json
+++ b/package.json
@@ -26,6 +26,7 @@
     "rc-slider": "^7.0.1"
   },
   "devDependencies": {
+    "chai": "^3.5.0",
     "react-scripts": "0.9.3"
   },
   "scripts": {