diff --git a/examples/zkapps/04-zkapp-browser-ui/ui/src/pages/zkappWorker.ts b/examples/zkapps/04-zkapp-browser-ui/ui/src/pages/zkappWorker.ts
index 12cf91014..ff855bc2e 100644
--- a/examples/zkapps/04-zkapp-browser-ui/ui/src/pages/zkappWorker.ts
+++ b/examples/zkapps/04-zkapp-browser-ui/ui/src/pages/zkappWorker.ts
@@ -1,4 +1,5 @@
 import { Mina, PublicKey, fetchAccount } from 'o1js';
+import * as Comlink from "comlink";
 
 type Transaction = Awaited<ReturnType<typeof Mina.transaction>>;