--- a/dom/events/test/browser_shortcutkey_modifier_conflicts_with_content_accesskey_modifier.js
+++ b/dom/events/test/browser_shortcutkey_modifier_conflicts_with_content_accesskey_modifier.js
@@ -41,22 +41,27 @@ add_task(async function() {
                gURLBar.inputField.selectionEnd === gURLBar.inputField.value.length;
       }
       if (isAllTextSelected()) {
         ok(true, "All text of the URL bar is already selected");
         isnot(gURLBar.inputField.value, "", "The URL bar should have non-empty text");
         resolve();
         return;
       }
-      info("Waiting selectionchange event...");
-      gURLBar.addEventListener("selectionchange", () => {
-        ok(isAllTextSelected(), "All text of the URL bar should be selected");
+      info("Waiting selection changes...");
+      function tryToCheckItLater() {
+        if (!isAllTextSelected()) {
+          SimpleTest.executeSoon(tryToCheckItLater);
+          return;
+        }
+        ok(true, "All text of the URL bar should be selected");
         isnot(gURLBar.inputField.value, "", "The URL bar should have non-empty text");
         resolve();
-      }, {once: true});
+      }
+      SimpleTest.executeSoon(tryToCheckItLater);
     });
   }
 
   // Alt + D is a shortcut key to move focus to the URL bar and selects its text.
   info("Pressing Alt + D in the search bar...");
   EventUtils.synthesizeKey("d", {code: "KeyD", altKey: true});
 
   await promiseURLBarHasFocus();