diff --git a/e2e/specs/03-feed/video-playback.spec.ts b/e2e/specs/03-feed/video-playback.spec.ts
index dbbd6a4..1fb8bc4 100644
--- a/e2e/specs/03-feed/video-playback.spec.ts
+++ b/e2e/specs/03-feed/video-playback.spec.ts
@@ -40,10 +40,19 @@ test.describe('Video — the lightbox plays it', () => {
     page,
     guest,
     signIn,
+    db,
   }) => {
     const g = await guest('VideoWatcher');
     const id = await seedVideo(g.jwt);
 
+    // The poster assertion below needs the ffmpeg thumbnail to EXIST — the lightbox binds
+    // `poster={upload.thumbnail_url ?? undefined}`, so the attribute is simply absent until
+    // compression finishes. Without this wait the test races the worker and fails against a
+    // cold stack (first run after `stack:down -v`, cold ffmpeg), which is exactly when a suite
+    // is least likely to be believed. The `src` assertion is unconditional; only the poster
+    // needs the wait.
+    await expect.poll(() => db.compressionStatus(id), { timeout: 60_000 }).toBe('done');
+
     await signIn(page, g);
     await page.goto('/feed');