diff --git a/package.json b/package.json
index f53dddb..58c0df9 100644
--- a/package.json
+++ b/package.json
@@ -12,6 +12,7 @@
     "LICENSE",
     "lib/index.js",
     "lib/index.esm.js",
+    "lib/index.umd.js",
     "lib/index.d.js",
     "lib/JsonRpc.d.ts"
   ],