diff --git a/toolkit/components/passwordmgr/test/mochitest/test_autocomplete_highlight_username_only_form.html b/toolkit/components/passwordmgr/test/mochitest/test_autocomplete_highlight_username_only_form.html
--- a/toolkit/components/passwordmgr/test/mochitest/test_autocomplete_highlight_username_only_form.html
+++ b/toolkit/components/passwordmgr/test/mochitest/test_autocomplete_highlight_username_only_form.html
@@ -28,11 +28,12 @@
 add_task(async function test_username_field_in_username_only_form_highlight_on_autocomplete() {
   const form = createLoginForm({
     action: "https://autocomplete",
     username: {
       autocomplete: "username"
-    }
+    },
+    password: false
   });
 
   await openPopupOn(form.uname);
   synthesizeKey("KEY_ArrowDown");
   await synthesizeKey("KEY_Enter");