diff --git a/test/mozcentral/Makefile.in b/test/mozcentral/Makefile.in
index 8c9face17..77b7a838d 100644
--- a/test/mozcentral/Makefile.in
+++ b/test/mozcentral/Makefile.in
@@ -12,7 +12,6 @@ include $(DEPTH)/config/autoconf.mk
 include $(topsrcdir)/config/rules.mk
 
 _BROWSER_TEST_FILES = \
-  head.js \
   browser_pdfjs_main.js \
   file_pdfjs_test.pdf \
   $(NULL)
diff --git a/test/mozcentral/browser_pdfjs_main.js b/test/mozcentral/browser_pdfjs_main.js
index d3f5dd646..884650892 100644
--- a/test/mozcentral/browser_pdfjs_main.js
+++ b/test/mozcentral/browser_pdfjs_main.js
@@ -6,97 +6,66 @@ const RELATIVE_DIR = "browser/extensions/pdfjs/test/";
 const TESTROOT = "http://example.com/browser/" + RELATIVE_DIR;
 
 function test() {
-  waitForExplicitFinish();
+  var tab;
 
-  var tab = gBrowser.addTab(TESTROOT + "file_pdfjs_test.pdf");
+  waitForExplicitFinish();
+  registerCleanupFunction(function() {
+    gBrowser.removeTab(tab);
+  });
+
+  tab = gBrowser.addTab(TESTROOT + "file_pdfjs_test.pdf");
   var newTabBrowser = gBrowser.getBrowserForTab(tab);
-  newTabBrowser.addEventListener("pagechange", function onPageChange() {
-    newTabBrowser.removeEventListener("pagechange", onPageChange, true);
+  newTabBrowser.addEventListener("load", function eventHandler() {
+    newTabBrowser.removeEventListener("load", eventHandler, true);
 
     var document = newTabBrowser.contentDocument,
         window = newTabBrowser.contentWindow;
 
-    //
-    // Overall sanity tests
-    //
-    ok(document.querySelector('div#viewer'), "document content has viewer UI");
-    ok('PDFJS' in window.wrappedJSObject, "window content has PDFJS object");
-
-    //
-    // Sidebar: open
-    //
-    var sidebar = document.querySelector('button#sidebarToggle'),
-        outerContainer = document.querySelector('div#outerContainer');
-
-    sidebar.click();
-    ok(outerContainer.classList.contains('sidebarOpen'), 'sidebar opens on click');
-
-    // Thumbnails are created asynchronously - wait for them
-    waitForElement(document, 'canvas#thumbnail2', function(error) {
-      if (error)
-        finish();
-
-      //
-      // Page change from thumbnail click
-      //
-      var pageNumber = document.querySelector('input#pageNumber');
-      is(parseInt(pageNumber.value), 1, 'initial page is 1');
-
-      var thumbnail = document.querySelector('canvas#thumbnail2');
-      ok(thumbnail, 'thumbnail2 is available');
-      if (thumbnail) {
-        thumbnail.click();
-        is(parseInt(pageNumber.value), 2, 'clicking on thumbnail changes page');
-      }
-
-      //
-      // Sidebar: close
-      //
-      sidebar.click();
-      ok(!outerContainer.classList.contains('sidebarOpen'), 'sidebar closes on click');
-
-      //
-      // Page change from prev/next buttons
-      //
-      var prevPage = document.querySelector('button#previous'),
-          nextPage = document.querySelector('button#next');
-
-      nextPage.click();
-      is(parseInt(pageNumber.value), 2, 'page increases after clicking on next');
-
-      prevPage.click();
-      is(parseInt(pageNumber.value), 1, 'page decreases after clicking on previous');
-
-      //
-      // Bookmark button
-      //
-      var viewBookmark = document.querySelector('a#viewBookmark');
-      viewBookmark.click();
-      ok(viewBookmark.href.length > 0, 'viewBookmark button has href');
-
-      //
-      // Zoom in/out
-      //
-      var zoomOut = document.querySelector('button.zoomOut'),
-          zoomIn = document.querySelector('button.zoomIn');
-
-      // Zoom in
-      var oldWidth = document.querySelector('canvas#page1').width;
-      zoomIn.click();
-      var newWidth = document.querySelector('canvas#page1').width;
-      ok(oldWidth < newWidth, 'zooming in increases page width (old: '+oldWidth+', new: '+newWidth+')');
-
-      // Zoom out
-      var oldWidth = document.querySelector('canvas#page1').width;
-      zoomOut.click();
-      var newWidth = document.querySelector('canvas#page1').width;
-      ok(oldWidth > newWidth, 'zooming out decreases page width (old: '+oldWidth+', new: '+newWidth+')');
-
-      finish();
-    });
-  }, true, true);
-
-  registerCleanupFunction(function() {
-    gBrowser.removeTab(tab);
-  });
+    // Runs tests after all 'load' event handlers have fired off
+    setTimeout(function() {
+      runTests(document, window);
+    }, 0);
+  }, true);
+}
+
+
+function runTests(document, window) {
+  //
+  // Overall sanity tests
+  //
+  ok(document.querySelector('div#viewer'), "document content has viewer UI");
+  ok('PDFJS' in window.wrappedJSObject, "window content has PDFJS object");
+
+  //
+  // Sidebar: open
+  //
+  var sidebar = document.querySelector('button#sidebarToggle'),
+      outerContainer = document.querySelector('div#outerContainer');
+
+  sidebar.click();
+  ok(outerContainer.classList.contains('sidebarOpen'), 'sidebar opens on click');
+
+  //
+  // Sidebar: close
+  //
+  sidebar.click();
+  ok(!outerContainer.classList.contains('sidebarOpen'), 'sidebar closes on click');
+
+  //
+  // Page change from prev/next buttons
+  //
+  var prevPage = document.querySelector('button#previous'),
+      nextPage = document.querySelector('button#next');
+
+  var pageNumber = document.querySelector('input#pageNumber');
+  is(parseInt(pageNumber.value), 1, 'initial page is 1');
+
+  //
+  // Bookmark button
+  //
+  var viewBookmark = document.querySelector('a#viewBookmark');
+  viewBookmark.click();
+  ok(viewBookmark.href.length > 0, 'viewBookmark button has href');
+
+  finish();
 }
diff --git a/test/mozcentral/head.js b/test/mozcentral/head.js
deleted file mode 100644
index 6ee421b2f..000000000
--- a/test/mozcentral/head.js
+++ /dev/null
@@ -1,21 +0,0 @@
-// Waits for element 'el' to exist in the DOM of 'doc' before executing 'callback'
-// Useful when elements are created asynchronously, e.g. after a Web Worker task
-function waitForElement(doc, el, callback) {
-  var time = 0,
-      interval = 10,
-      timeout = 5000;
-
-  var checkEl = setInterval(function() {
-    if (doc.querySelector(el)) {
-      clearInterval(checkEl);
-      if (callback) callback();
-    }
-
-    time += interval;
-    if (time > timeout) {
-      ok(false, 'waitForElement timed out on element: '+el);
-      clearInterval(checkEl);
-      if (callback) callback(true);
-    }
-  }, interval);
-}