diff -u b/core/modules/forum/templates/forum-icon.html.twig b/core/modules/forum/templates/forum-icon.html.twig
--- b/core/modules/forum/templates/forum-icon.html.twig
+++ b/core/modules/forum/templates/forum-icon.html.twig
@@ -18,7 +18,7 @@
  * @ingroup themeable
  */
 #}
-<div>
+<div{{ attributes }}>
   {% if first_new -%}
     <a id="new"></a>
   {%- endif %}