diff --git a/browser/base/content/test/general/browser_customize_popupNotification.js b/browser/base/content/test/general/browser_customize_popupNotification.js
index 8d7737249cc0..4dea7b497607 100644
--- a/browser/base/content/test/general/browser_customize_popupNotification.js
+++ b/browser/base/content/test/general/browser_customize_popupNotification.js
@@ -1,41 +1,35 @@
-/* Any copyright is dedicated to the Public Domain.
- * http://creativecommons.org/publicdomain/zero/1.0/ */
+/*
+Any copyright is dedicated to the Public Domain.
+http://creativecommons.org/publicdomain/zero/1.0/
+*/
 
-add_task(function* () {
-  let win = yield promiseOpenAndLoadWindow({}, true /* wait for delayed startup */);
+function test() {
+  waitForExplicitFinish();
+  let newWin = OpenBrowserWindow();
+  registerCleanupFunction(() => {
+    newWin.close()
+    newWin = null;
+  });
+  whenDelayedStartupFinished(newWin, function () {
+    // Remove the URL bar
+    newWin.gURLBar.parentNode.removeChild(newWin.gURLBar);
 
-  // Remove the navigation toolbar.
-  win.document.getElementById("nav-bar").remove();
-
-  yield new Promise(resolve => waitForFocus(resolve, win));
-  yield promiseBrowserLoaded(win.gBrowser.browsers[0]);
-
-  try {
-    let PN = win.PopupNotifications;
-    let panelPromise = promisePopupShown(PN.panel);
-    let notification = PN.show(win.gBrowser.selectedBrowser, "some-notification", "Some message");
-    ok(notification, "show() succeeded");
-    yield panelPromise;
-
-    ok(PN.isPanelOpen, "panel is open");
-    is(PN.panel.anchorNode, win.gBrowser.selectedTab, "notification is correctly anchored to the tab");
-    PN.panel.hidePopup();
-  } catch (ex) {
-    ok(false, "threw exception: " + ex);
-  }
-
-  yield promiseWindowClosed(win);
-});
-
-function promiseBrowserLoaded(browser) {
-  if (browser.contentDocument.readyState == "complete") {
-    return Promise.resolve();
-  }
-
-  return new Promise(resolve => {
-    browser.addEventListener("load", function onLoad() {
-      browser.removeEventListener("load", onLoad, true);
-      resolve();
-    }, true);
+    waitForFocus(function () {
+      let PN = newWin.PopupNotifications;
+      try {
+        let panelPromise = promisePopupShown(PN.panel);
+        let notification = PN.show(newWin.gBrowser.selectedBrowser, "some-notification", "Some message");
+        panelPromise.then(function() {
+          ok(notification, "showed the notification");
+          ok(PN.isPanelOpen, "panel is open");
+          is(PN.panel.anchorNode, newWin.gBrowser.selectedTab, "notification is correctly anchored to the tab");
+          PN.panel.hidePopup();
+          finish();
+        });
+      } catch (ex) {
+        ok(false, "threw exception: " + ex);
+        finish();
+      }
+    }, newWin);
   });
 }