diff --git a/core/modules/language/language.admin.inc b/core/modules/language/language.admin.inc
index 3baf045..7fdaf1a 100644
--- a/core/modules/language/language.admin.inc
+++ b/core/modules/language/language.admin.inc
@@ -7,6 +7,7 @@
 
 use Drupal\Component\Utility\String;
 use Drupal\Core\Render\Element;
+use Drupal\Core\Template\Attribute;
 
 /**
  * Prepares variables for language negotiation configuration form.
@@ -84,11 +85,11 @@ function template_preprocess_language_negotiation_configure_form(&$variables) {
       'configurable' => $configurable,
       'table' => $table,
       'children' => $form[$type],
+      'attributes' => new Attribute,
     );
     // Prevent the type from rendering with the remaining form child elements.
     unset($form[$type]);
   }
-
   $variables['children'] = $form;
 }
 
diff --git a/core/modules/language/templates/language-negotiation-configure-form.html.twig b/core/modules/language/templates/language-negotiation-configure-form.html.twig
index 67ddda4..8e1c8f5 100644
--- a/core/modules/language/templates/language-negotiation-configure-form.html.twig
+++ b/core/modules/language/templates/language-negotiation-configure-form.html.twig
@@ -12,6 +12,7 @@
 *   - configurable: A radio element to toggle the table.
 *   - table: A draggable table for the language detection methods of this type.
 *   - children: Remaining form items for the group.
+*   - attributes: A list of HTML attributes for the wrapper element.
 * - children: Remaining form items for all groups.
 *
 * @see template_preprocess_language_negotiation_configure_form()
@@ -20,7 +21,14 @@
 */
 #}
 {% for language_type in language_types %}
-  <div class="form-item table-language-group table-{{ language_type.type }}-wrapper">
+  {%
+    set language_classes = [
+      'form-item',
+      'table-language-group',
+      'table-' ~ language_type.type ~ '-wrapper',
+    ]
+  %}
+  <div{{ language_type.attributes.addClass(language_classes) }}>
     <h2>{{ language_type.title }}</h2>
     <div class="description">{{ language_type.description }}</div>
     {{ language_type.configurable }}