diff --git a/testing/web-platform/tests/mediacapture-insertable-streams/VideoTrackGenerator-with-window-tracks.https.html b/testing/web-platform/tests/mediacapture-insertable-streams/VideoTrackGenerator-with-window-tracks.https.html
index 36fc4135e2344..dfe000fbddb6c 100644
--- a/testing/web-platform/tests/mediacapture-insertable-streams/VideoTrackGenerator-with-window-tracks.https.html
+++ b/testing/web-platform/tests/mediacapture-insertable-streams/VideoTrackGenerator-with-window-tracks.https.html
@@ -64,11 +64,15 @@ <h1 class="instructions">Description</h1>
       const blob = new Blob([script], { type: 'text/javascript' });
       const url = URL.createObjectURL(blob);
       const worker = new Worker(url);
-      await new Promise(resolve => worker.onmessage = () => {
-          resolve();
-      });
-      URL.revokeObjectURL(url);
-      return worker;
+      try {
+        await new Promise((resolve, reject) => {
+          worker.onmessage = resolve;
+          worker.onerror = (err) => reject(err.message);
+        });
+        return worker;
+      } finally {
+        URL.revokeObjectURL(url);
+      }
     }
 
    promise_test(async t => {