diff --git a/package.json b/package.json
index 0986f6ae88..a57b551873 100644
--- a/package.json
+++ b/package.json
@@ -146,6 +146,7 @@
   },
   "homepage": "https://github.com/ReactiveX/RxJS",
   "devDependencies": {
+    "babel-polyfill": "^6.23.0",
     "benchmark": "^2.1.0",
     "benchpress": "2.0.0-beta.1",
     "chai": "^3.5.0",