diff --git a/browser/base/content/test/keyboard/browser_bookmarks_shortcut.js b/browser/base/content/test/keyboard/browser_bookmarks_shortcut.js
index 29ab55b904b093c38dd8a02060478f36f89516e9..5437598e92c84c70d2fcd17bcb174e64eea9159e 100644
--- a/browser/base/content/test/keyboard/browser_bookmarks_shortcut.js
+++ b/browser/base/content/test/keyboard/browser_bookmarks_shortcut.js
@@ -130,7 +130,7 @@ async function openContextMenu(contextMenu, target) {
   await BrowserTestUtils.waitForPopupEvent(contextMenu, "shown");
   let bookmarksToolbarMenu = document.querySelector("#toggle_PersonalToolbar");
   let subMenu = bookmarksToolbarMenu.querySelector("menupopup");
-  EventUtils.synthesizeMouseAtCenter(bookmarksToolbarMenu, {});
+  bookmarksToolbarMenu.openMenu(true);
   await BrowserTestUtils.waitForPopupEvent(subMenu, "shown");
 }