diff --git a/web/default_preferences.js b/web/default_preferences.js
deleted file mode 100644
index b8fed8c18..000000000
--- a/web/default_preferences.js
+++ /dev/null
@@ -1,36 +0,0 @@
-/* Copyright 2013 Mozilla Foundation
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-'use strict';
-
-var DEFAULT_PREFERENCES;
-
-(function defaultPreferencesLoaderWrapper() {
-  function loaded() {
-    try {
-      DEFAULT_PREFERENCES = JSON.parse(xhr.responseText);
-    } catch (e) {
-      console.error('Unable to load DEFAULT_PREFERENCES: ' + e);
-      DEFAULT_PREFERENCES = {};
-    }
-    var event = document.createEvent('CustomEvent');
-    event.initCustomEvent('defaultpreferencesloaded', true, true, null);
-    document.dispatchEvent(event);
-  }
-  var xhr = new XMLHttpRequest();
-  xhr.open('GET', 'default_preferences.json');
-  xhr.onload = xhr.onerror = loaded;
-  xhr.send();
-})();
diff --git a/web/preferences.js b/web/preferences.js
index 49907315e..471808fd8 100644
--- a/web/preferences.js
+++ b/web/preferences.js
@@ -12,7 +12,6 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-/* globals DEFAULT_PREFERENCES */
 
 'use strict';
 
@@ -26,21 +25,29 @@
   }
 }(this, function (exports) {
 
-var defaultPreferences;
-if (typeof PDFJSDev !== 'undefined' && PDFJSDev.test('PRODUCTION')) {
-  defaultPreferences = Promise.resolve(
-    PDFJSDev.json('$ROOT/web/default_preferences.json'));
-} else {
-  defaultPreferences = new Promise(function (resolve) {
-    if (DEFAULT_PREFERENCES) {
-      resolve(DEFAULT_PREFERENCES);
-      return;
+var defaultPreferences = null;
+function getDefaultPreferences() {
+  if (!defaultPreferences) {
+    if (typeof PDFJSDev !== 'undefined' && PDFJSDev.test('PRODUCTION')) {
+      defaultPreferences = Promise.resolve(
+        PDFJSDev.json('$ROOT/web/default_preferences.json'));
+    } else {
+      defaultPreferences = new Promise(function (resolve) {
+        var xhr = new XMLHttpRequest();
+        xhr.open('GET', 'default_preferences.json');
+        xhr.onload = xhr.onerror = function loaded() {
+          try {
+            resolve(JSON.parse(xhr.responseText));
+          } catch (e) {
+            console.error('Unable to load default preferences: ' + e);
+            resolve({});
+          }
+        };
+        xhr.send();
+      });
     }
-    document.addEventListener('defaultpreferencesloaded', function loaded() {
-      resolve(DEFAULT_PREFERENCES);
-      document.removeEventListener('defaultpreferencesloaded', loaded);
-    });
-  });
+  }
+  return defaultPreferences;
 }
 
 function cloneObj(obj) {
@@ -69,7 +76,7 @@ var Preferences = {
    *                   have been initialized.
    */
   initialize: function preferencesInitialize() {
-    return this.initializedPromise = defaultPreferences.then(
+    return this.initializedPromise = getDefaultPreferences().then(
         function (defaults) {
 
       Object.defineProperty(this, 'defaults', {
diff --git a/web/viewer.html b/web/viewer.html
index d45bde539..22ff8af8e 100644
--- a/web/viewer.html
+++ b/web/viewer.html
@@ -60,10 +60,6 @@ See https://github.com/adobe-type-tools/cmap-resources
 <!--#include viewer-snippet.html-->
 <!--#endif-->
 
-<!--#if !PRODUCTION-->
-    <script src="default_preferences.js"></script>
-<!--#endif-->
-
 <!--#if !MINIFIED -->
     <script src="viewer.js"></script>
 <!--#else-->
diff --git a/web/viewer.js b/web/viewer.js
index a743e7e08..01c27a608 100644
--- a/web/viewer.js
+++ b/web/viewer.js
@@ -169,15 +169,9 @@ function webViewerLoad() {
   var config = getViewerConfiguration();
   if (typeof PDFJSDev === 'undefined' || !PDFJSDev.test('PRODUCTION')) {
     require.config({paths: {'pdfjs': '../src', 'pdfjs-web': '.'}});
-    require(['pdfjs-web/pdfjs'], function () {
-      // Ensure that src/main_loader.js has loaded all the necessary
-      // dependencies *before* the viewer loads, to prevent issues in browsers
-      // relying on e.g. the Promise/URL polyfill in src/shared/util.js (fixes
-      // issue 7448).
-      require(['pdfjs-web/app', 'pdfjs-web/pdf_print_service'], function (web) {
-        window.PDFViewerApplication = web.PDFViewerApplication;
-        web.PDFViewerApplication.run(config);
-      });
+    require(['pdfjs-web/app', 'pdfjs-web/pdf_print_service'], function (web) {
+      window.PDFViewerApplication = web.PDFViewerApplication;
+      web.PDFViewerApplication.run(config);
     });
   } else {
     window.PDFViewerApplication = pdfjsWebLibs.pdfjsWebApp.PDFViewerApplication;
@@ -185,4 +179,9 @@ function webViewerLoad() {
   }
 }
 
-document.addEventListener('DOMContentLoaded', webViewerLoad, true);
+if (document.readyState === 'interactive' ||
+    document.readyState === 'complete') {
+  webViewerLoad();
+} else {
+  document.addEventListener('DOMContentLoaded', webViewerLoad, true);
+}