diff --git a/extensions/zalo/src/monitor.reply-once.lifecycle.test.ts b/extensions/zalo/src/monitor.reply-once.lifecycle.test.ts
index c8a23e5d4ad..807606306b6 100644
--- a/extensions/zalo/src/monitor.reply-once.lifecycle.test.ts
+++ b/extensions/zalo/src/monitor.reply-once.lifecycle.test.ts
@@ -60,6 +60,15 @@ describe("Zalo reply-once lifecycle", () => {
     });
   }
 
+  function requireRecordInboundSessionArgs() {
+    const [call] = recordInboundSessionMock.mock.calls;
+    if (!call) {
+      throw new Error("expected inbound session record call");
+    }
+    const [recordArgs] = call;
+    return recordArgs;
+  }
+
   it("routes one accepted webhook event to one visible reply across duplicate replay", async () => {
     dispatchReplyWithBufferedBlockDispatcherMock.mockImplementation(
       async ({ dispatcherOptions }) => {
@@ -95,7 +104,7 @@ describe("Zalo reply-once lifecycle", () => {
       );
 
       expect(recordInboundSessionMock).toHaveBeenCalledTimes(1);
-      const [recordArgs] = recordInboundSessionMock.mock.calls[0] ?? [];
+      const recordArgs = requireRecordInboundSessionArgs();
       expect(recordArgs?.sessionKey).toBe("agent:main:zalo:direct:dm-chat-1");
       expect(recordArgs?.ctx?.AccountId).toBe("acct-zalo-lifecycle");
       expect(recordArgs?.ctx?.SessionKey).toBe("agent:main:zalo:direct:dm-chat-1");