diff --git a/content/canvas/test/test_toBlob.html b/content/canvas/test/test_toBlob.html
index 0ebc3fce7d2..537bb27d3eb 100644
--- a/content/canvas/test/test_toBlob.html
+++ b/content/canvas/test/test_toBlob.html
@@ -1,5 +1,5 @@
 <!DOCTYPE HTML>
-<title>Canvas test: mozGetAsFile</title>
+<title>Canvas test: toBlob</title>
 <script src="/MochiKit/MochiKit.js"></script>
 <script src="/tests/SimpleTest/SimpleTest.js"></script>
 <link rel="stylesheet" href="/tests/SimpleTest/test.css">
@@ -7,34 +7,40 @@
 <canvas id="c" width="100" height="50"><p class="fallback">FAIL (fallback content)</p></canvas>
 <script>
 
-var gCompares = 2;
-
-function BlobListener(type, canvas, file)
+function BlobListener(type, canvas, callback, file)
 {
   is(file.type, type,
      "When a valid type is specified that should be returned");
   var reader = new FileReader();
-  reader.onload = 
+  reader.onload =
     function(e) {
       is(e.target.result, canvas.toDataURL(type),
- "<canvas>.mozGetAsFile().getAsDataURL() should equal <canvas>.toDataURL()");
-      if (--gCompares == 0) {
-        SimpleTest.finish();
-      }
+  "<canvas>.mozGetAsFile().getAsDataURL() should equal <canvas>.toDataURL()");
+      callback(canvas);
     };
   reader.readAsDataURL(file);
 }
 
+function test1(canvas)
+{
+  canvas.toBlob(BlobListener.bind(undefined, "image/png", canvas, test2));
+}
+
+function test2(canvas)
+{
+  canvas.toBlob(
+    BlobListener.bind(undefined, "image/jpeg", canvas, SimpleTest.finish),
+    "image/jpeg");
+}
+
 SimpleTest.waitForExplicitFinish();
 addLoadEvent(function () {
 
 var canvas = document.getElementById('c');
 var ctx = canvas.getContext('2d');
-
 ctx.drawImage(document.getElementById('yellow75.png'), 0, 0);
 
-canvas.toBlob(BlobListener.bind(undefined, "image/png", canvas));
-canvas.toBlob(BlobListener.bind(undefined, "image/jpeg", canvas), "image/jpeg");
+test1(canvas);
 
 });
 </script>
