diff --git a/packages/fieldlens-core/src/lib/database.test.ts b/packages/fieldlens-core/src/lib/database.test.ts
index f6d8e3c..b3297cb 100644
--- a/packages/fieldlens-core/src/lib/database.test.ts
+++ b/packages/fieldlens-core/src/lib/database.test.ts
@@ -67,8 +67,9 @@ describe('scan persistence', () => {
   it('marks only explicitly acknowledged events synced', async () => {
     const first = await recordScan('ONE', 'Code 128')
     await recordScan('TWO', 'Code 128')
-    const events = await database.outbox.toArray()
-    await acknowledgeOutboxEvent(events[0]!.id)
+    const event = await database.outbox.where('aggregateId').equals(first.id).first()
+    expect(event).toBeDefined()
+    await acknowledgeOutboxEvent(event!.id)
     const stats = await getOutboxStats()
     expect(stats.synced).toBe(1)
     expect(stats.pending).toBe(1)