diff --git a/content/media/test/test_mediarecorder_record_no_timeslice.html b/content/media/test/test_mediarecorder_record_no_timeslice.html
index 5d0270e013de..632835a57fa9 100644
--- a/content/media/test/test_mediarecorder_record_no_timeslice.html
+++ b/content/media/test/test_mediarecorder_record_no_timeslice.html
@@ -10,6 +10,8 @@
 <pre id="test">
 <script class="testbody" type="text/javascript">
 var manager = new MediaTestManager;
+// Need to clarify why declare mediaRecorder in startTest cause timeout.;
+var mediaRecorder;
 
 /**
  * Starts a test on every media recorder file included to check that a
@@ -26,7 +28,7 @@ function startTest(test, token) {
   element.test = test;
   element.stream = element.mozCaptureStreamUntilEnded();
 
-  var mediaRecorder = new MediaRecorder(element.stream);
+  mediaRecorder = new MediaRecorder(element.stream);
   var onStopFired = false;
   var onDataAvailableFired = false;