--- a/browser/base/content/test/alerts/browser_notification_open_settings.js
+++ b/browser/base/content/test/alerts/browser_notification_open_settings.js
@@ -1,22 +1,28 @@
 "use strict";
 
 var notificationURL = "http://example.org/browser/browser/base/content/test/alerts/file_dom_notifications.html";
-var expectedURL = Services.prefs.getBoolPref("browser.preferences.useOldOrganization") ? "about:preferences#content"
-                                                                                       : "about:preferences#privacy";
+var useOldPrefs = Services.prefs.getBoolPref("browser.preferences.useOldOrganization");
+var expectedURL = useOldPrefs ? "about:preferences#content"
+                              : "about:preferences#privacy";
+
 
 add_task(async function test_settingsOpen_observer() {
   info("Opening a dummy tab so openPreferences=>switchToTabHavingURI doesn't use the blank tab.");
   await BrowserTestUtils.withNewTab({
     gBrowser,
     url: "about:robots"
   }, async function dummyTabTask(aBrowser) {
-    // Ensure preferences is loaded before removing the tab.
-    let syncPaneLoadedPromise = TestUtils.topicObserved("sync-pane-loaded", () => true);
+    // Ensure preferences is loaded before removing the tab. In the "new prefs", all categories
+    // get initialized on page load since we need to be able to search them. Sync is *very*
+    // slow to load and therefore we need to wait for it to load when testing the "new prefs".
+    // For "old prefs" we only load the actual visited categories so we don't have this problem,
+    // as well, the "sync-pane-loaded" notification is not sent on "old prefs".
+    let syncPaneLoadedPromise = useOldPrefs || TestUtils.topicObserved("sync-pane-loaded", () => true);
 
     let tabPromise = BrowserTestUtils.waitForNewTab(gBrowser, expectedURL);
     info("simulate a notifications-open-settings notification");
     let uri = NetUtil.newURI("https://example.com");
     let principal = Services.scriptSecurityManager.createCodebasePrincipal(uri, {});
     Services.obs.notifyObservers(principal, "notifications-open-settings");
     let tab = await tabPromise;
     ok(tab, "The notification settings tab opened");
@@ -30,18 +36,22 @@ add_task(async function test_settingsOpe
   info("Adding notification permission");
   pm.add(makeURI(notificationURL), "desktop-notification", pm.ALLOW_ACTION);
 
   try {
     await BrowserTestUtils.withNewTab({
       gBrowser,
       url: notificationURL
     }, async function tabTask(aBrowser) {
-      // Ensure preferences is loaded before removing the tab.
-      let syncPaneLoadedPromise = TestUtils.topicObserved("sync-pane-loaded", () => true);
+      // Ensure preferences is loaded before removing the tab. In the "new prefs", all categories
+      // get initialized on page load since we need to be able to search them. Sync is *very*
+      // slow to load and therefore we need to wait for it to load when testing the "new prefs".
+      // For "old prefs" we only load the actual visited categories so we don't have this problem,
+      // as well, the "sync-pane-loaded" notification is not sent on "old prefs".
+      let syncPaneLoadedPromise = useOldPrefs || TestUtils.topicObserved("sync-pane-loaded", () => true);
 
       info("Waiting for notification");
       await openNotification(aBrowser, "showNotification2");
 
       let alertWindow = Services.wm.getMostRecentWindow("alert:alert");
       if (!alertWindow) {
         ok(true, "Notifications don't use XUL windows on all platforms.");
         await closeNotification(aBrowser);