--- a/dom/media/mediasource/test/test_HaveMetadataUnbufferedSeek_mp4.html
+++ b/dom/media/mediasource/test/test_HaveMetadataUnbufferedSeek_mp4.html
@@ -28,16 +28,19 @@ runWithMSE(function (ms, v) {
       ok(v.readyState >= v.HAVE_CURRENT_DATA, "readyState is >= CURRENT_DATA");
       v.currentTime = target;
     });
 
     v.addEventListener("seeking", function () {
       is(v.readyState, v.HAVE_METADATA, "readyState is HAVE_METADATA");
       fetchWithXHR("bipbop/bipbop2s.mp4", function (arrayBuffer) {
         // 25819 is the offset of the first media segment's end
+        sb.addEventListener("updateend", function () {
+          ms.endOfStream();
+        });
         sb.appendBuffer(new Uint8Array(arrayBuffer, 25819));
       });
     });
 
     v.addEventListener("seeked", function () {
       SimpleTest.finish();
     });
   });