diff --git a/core/themes/seven/seven.theme b/core/themes/seven/seven.theme
index f4dd82b..ea523ad 100644
--- a/core/themes/seven/seven.theme
+++ b/core/themes/seven/seven.theme
@@ -78,7 +78,6 @@ function seven_preprocess_node_add_list(&$variables) {
  *
  * Displays the list of available custom block types for creation, adding
  * separate variables for the label and the path.
- *
  */
 function seven_preprocess_custom_block_add_list(&$variables) {
   if (!empty($variables['content'])) {
@@ -98,7 +97,14 @@ function seven_preprocess_custom_block_add_list(&$variables) {
  */
 function seven_preprocess_admin_block_content(&$variables) {
   if (!empty($variables['content'])) {
-    $variables['compact'] = system_admin_compact_mode() ? 'compact' : '';
+    // @todo Remove once theme_admin_block() is converted to Twig.
+    // See https://drupal.org/node/1987410
+    $compact = system_admin_compact_mode();
+    $variables['attributes'] = array('class' => array('admin-list'));
+    if ($compact) {
+      $variables['attributes']['class'][] = 'compact';
+    }
+
     foreach ($variables['content'] as $key => $item) {
       $variables['content'][$key]['label'] = Xss::filterAdmin($item['title']);
       $variables['content'][$key]['path'] = url($item['href']);
diff --git a/core/themes/seven/templates/admin-block-content.html.twig b/core/themes/seven/templates/admin-block-content.html.twig
index 8960563..f92fa22 100644
--- a/core/themes/seven/templates/admin-block-content.html.twig
+++ b/core/themes/seven/templates/admin-block-content.html.twig
@@ -8,16 +8,16 @@
  *   - path: Path to the admin section.
  *   - label: Short name of the section.
  *   - description: Description of the administrative menu item.
- * - compact: Class indicator for compact mode (empty if not compact).
+ * - attributes: HTML attributes to be added to the element.
  *
  * @see template_preprocess_admin_block_content()
- * @see seven_preprocess_custom_block_add_list()
+ * @see seven_preprocess_admin_block_content()
  *
  * @ingroup themeable
  */
 #}
 {% if content %}
-  <ul class="admin-list {{ compact }}">
+  <ul{{ attributes }}>
     {% for item in content %}
       <li><a href="{{ item.path }}"><span class="label">{{ item.label }}</span><div class="description">{{ item.description }}</div></a></li>
     {% endfor %}