diff --git a/examples/zkapps/01-hello-world/src/main.ts b/examples/zkapps/01-hello-world/src/main.ts
index c0d2666fc..470c4f43c 100644
--- a/examples/zkapps/01-hello-world/src/main.ts
+++ b/examples/zkapps/01-hello-world/src/main.ts
@@ -54,7 +54,7 @@ try {
   const txn2 = await Mina.transaction(senderAccount, () => {
     zkAppInstance.update(Field(75));
   });
-  await txn1.prove();
+  await txn2.prove();
   await txn2.sign([senderKey]).send();
 } catch (ex: any) {
   console.log(ex.message);