diff --git a/layout/reftests/ogg-video/444-1-ref.html b/layout/reftests/ogg-video/444-1-ref.html
index 287361bfb1fa..b544a4b4da79 100644
--- a/layout/reftests/ogg-video/444-1-ref.html
+++ b/layout/reftests/ogg-video/444-1-ref.html
@@ -1,15 +1,20 @@
 <!DOCTYPE HTML>
 <html class="reftest-wait">
 <body>
-<video id="v1" src="seek420.ogv" style="position:absolute; left:0; top:0"></video>
+<video id="v1" style="position:absolute; left:0; top:0"></video>
 <!-- hide bottom of video -->
 <div style="position:absolute; top:120px; left:0; right:0; bottom:0; background:black"></div>
 <script>
 function doTest() {
+  // Set source now so that the loadeddata event can't fire before
+  // this function runs.
+  v1.src = "seek420.ogv";
   v1.play();
-  setTimeout(function() {
-    document.documentElement.removeAttribute('class');
-  }, 500);
+  v1.addEventListener("loadeddata", function() {
+    setTimeout(function() {
+      document.documentElement.removeAttribute('class');
+    }, 50);
+  });
 }
 document.addEventListener("MozReftestInvalidate", doTest, false);
 </script>
diff --git a/layout/reftests/ogg-video/444-1.html b/layout/reftests/ogg-video/444-1.html
index 24a52ff9882d..2921ea07dc40 100644
--- a/layout/reftests/ogg-video/444-1.html
+++ b/layout/reftests/ogg-video/444-1.html
@@ -1,15 +1,20 @@
 <!DOCTYPE HTML>
 <html class="reftest-wait">
 <body>
-<video id="v1" src="seek444.ogv" style="position:absolute; left:0; top:0"></video>
+<video id="v1" style="position:absolute; left:0; top:0"></video>
 <!-- hide bottom of video -->
 <div style="position:absolute; top:120px; left:0; right:0; bottom:0; background:black"></div>
 <script>
 function doTest() {
+  // Set source now so that the loadeddata event can't fire before
+  // this function runs.
+  v1.src = "seek444.ogv";
   v1.play();
-  setTimeout(function() {
-    document.documentElement.removeAttribute('class');
-  }, 500);
+  v1.addEventListener("loadeddata", function() {
+    setTimeout(function() {
+      document.documentElement.removeAttribute('class');
+    }, 50);
+  });
 }
 document.addEventListener("MozReftestInvalidate", doTest, false);
 </script>
