diff --git a/package.json b/package.json
index 35d573d..d014cb8 100644
--- a/package.json
+++ b/package.json
@@ -3,6 +3,7 @@
   "version": "1.0.0",
   "description": "Radial Tree Library for Wayback Machine",
   "main": "build/js/radial-tree.min.js",
+  "module": "src/js/index.js",
   "directories": {
     "doc": "docs",
     "test": "test"