diff --git a/browser/base/content/test/tabs/browser_multiselect_tabs_reopen_in_container.js b/browser/base/content/test/tabs/browser_multiselect_tabs_reopen_in_container.js
index 629b0f8de3fee26fa9995f3e5c9dd77789d7d206..d190ef8b9b5555c60d12a55338db9b40fbb3a6c3 100644
--- a/browser/base/content/test/tabs/browser_multiselect_tabs_reopen_in_container.js
+++ b/browser/base/content/test/tabs/browser_multiselect_tabs_reopen_in_container.js
@@ -17,7 +17,7 @@ async function openTabMenuFor(tab) {
 }
 
 async function openReopenMenuForTab(tab) {
-  openTabMenuFor(tab);
+  await openTabMenuFor(tab);
 
   let reopenItem = tab.ownerDocument.getElementById(
     "context_reopenInContainer"
@@ -26,11 +26,7 @@ async function openReopenMenuForTab(tab) {
 
   let reopenMenu = reopenItem.getElementsByTagName("menupopup")[0];
   let reopenMenuShown = BrowserTestUtils.waitForEvent(reopenMenu, "popupshown");
-  EventUtils.synthesizeMouseAtCenter(
-    reopenItem,
-    { type: "mousemove" },
-    tab.ownerGlobal
-  );
+  reopenItem.openMenu(true);
   await reopenMenuShown;
 
   return reopenMenu;
@@ -56,7 +52,7 @@ function openTabInContainer(gBrowser, tab, reopenMenu, id) {
   let menuitem = reopenMenu.querySelector(
     `menuitem[data-usercontextid="${id}"]`
   );
-  EventUtils.synthesizeMouseAtCenter(menuitem, {}, menuitem.ownerGlobal);
+  reopenMenu.activateItem(menuitem);
   return tabPromise;
 }
 
diff --git a/browser/components/contextualidentity/test/browser/browser_reopenIn.js b/browser/components/contextualidentity/test/browser/browser_reopenIn.js
index 2f89bf17f527a923aab9d9336df566fbcc42f0b5..9bda63b201c208fd98c0671f770eddc8a5977a13 100644
--- a/browser/components/contextualidentity/test/browser/browser_reopenIn.js
+++ b/browser/components/contextualidentity/test/browser/browser_reopenIn.js
@@ -21,7 +21,7 @@ async function openTabMenuFor(tab) {
 }
 
 async function openReopenMenuForTab(tab) {
-  openTabMenuFor(tab);
+  await openTabMenuFor(tab);
 
   let reopenItem = tab.ownerDocument.getElementById(
     "context_reopenInContainer"
@@ -30,11 +30,7 @@ async function openReopenMenuForTab(tab) {
 
   let reopenMenu = reopenItem.getElementsByTagName("menupopup")[0];
   let reopenMenuShown = BrowserTestUtils.waitForEvent(reopenMenu, "popupshown");
-  EventUtils.synthesizeMouseAtCenter(
-    reopenItem,
-    { type: "mousemove" },
-    tab.ownerGlobal
-  );
+  reopenItem.openMenu(true);
   await reopenMenuShown;
 
   return reopenMenu;
@@ -60,7 +56,7 @@ function openTabInContainer(gBrowser, reopenMenu, id) {
   let menuitem = reopenMenu.querySelector(
     `menuitem[data-usercontextid="${id}"]`
   );
-  EventUtils.synthesizeMouseAtCenter(menuitem, {}, menuitem.ownerGlobal);
+  reopenMenu.activateItem(menuitem);
   return tabPromise;
 }
 
@@ -128,12 +124,12 @@ add_task(async function testDisabled() {
     "Tab with No Container should be opened"
   );
 
-  openTabMenuFor(tab);
+  let tabMenu = await openTabMenuFor(tab);
   let reopenItem = document.getElementById("context_reopenInContainer");
   ok(reopenItem.hidden, "Reopen in Container item should be hidden");
 
   // Close the tab menu.
-  EventUtils.synthesizeKey("KEY_Escape");
+  tabMenu.hidePopup();
 
   BrowserTestUtils.removeTab(tab);
 });
@@ -155,14 +151,14 @@ add_task(async function testPrivateMode() {
     "Tab with No Container should be opened"
   );
 
-  openTabMenuFor(tab);
+  let tabMenu = await openTabMenuFor(tab);
   let reopenItem = privateWindow.document.getElementById(
     "context_reopenInContainer"
   );
   ok(reopenItem.hidden, "Reopen in Container item should be hidden");
 
   // Close the tab menu.
-  EventUtils.synthesizeKey("KEY_Escape");
+  tabMenu.hidePopup();
 
   await BrowserTestUtils.closeWindow(privateWindow);
 });
diff --git a/browser/components/contextualidentity/test/browser/head.js b/browser/components/contextualidentity/test/browser/head.js
index f02c49f248985c7c3c7f14cdad78db22c5f7bf6c..b5bf451d2537d65a787c0058b44493b0821c7cb4 100644
--- a/browser/components/contextualidentity/test/browser/head.js
+++ b/browser/components/contextualidentity/test/browser/head.js
@@ -13,22 +13,20 @@ async function openTabMenuFor(tab) {
 }
 
 async function openReopenMenuForTab(tab) {
-  openTabMenuFor(tab);
+  await openTabMenuFor(tab);
 
   let reopenItem = tab.ownerDocument.getElementById(
     "context_reopenInContainer"
   );
   ok(!reopenItem.hidden, "Reopen in Container item should be shown");
 
-  const menuPopup = tab.ownerDocument.getElementById(
-    "context_reopenInContainer"
-  ).menupopup;
+  const menuPopup = reopenItem.menupopup;
   const menuPopupPromise = BrowserTestUtils.waitForEvent(
     menuPopup,
     "popupshown"
   );
   info(`About to open a popup`);
-  menuPopup.openPopup();
+  reopenItem.openMenu(true);
   info(`Waiting for the menu popup promise`);
   await menuPopupPromise;
   info(`Awaited menu popup promise`);
@@ -40,7 +38,8 @@ function openTabInContainer(gBrowser, url, reopenMenu, id) {
   let menuitem = reopenMenu.querySelector(
     `menuitem[data-usercontextid="${id}"]`
   );
-  EventUtils.synthesizeMouseAtCenter(menuitem, {}, menuitem.ownerGlobal);
+  info(`about to activate item`);
+  reopenMenu.activateItem(menuitem);
   return tabPromise;
 }