reverted: --- b/core/modules/system/lib/Drupal/system/Tests/Common/RenderElementTypesTest.php +++ a/core/modules/system/lib/Drupal/system/Tests/Common/RenderElementTypesTest.php @@ -217,7 +217,7 @@ '!head_title' => $site_config->get('name'), '!styles' => drupal_get_css($css), '!scripts' => drupal_get_js(), + '!attributes.class' => 'maintenance-page in-maintenance no-sidebars', - '!attributes.class' => 'page--maintenance page--maintenance-in-maintenance', '!front_page' => url(), '!logo' => theme_get_setting('logo.url'), '!site_name' => $site_config->get('name'),