diff --git a/themes/de_105/templates/Recommend/SideFacets.phtml b/themes/de_105/templates/Recommend/SideFacets.phtml
index 46c63df021cfe850359f86caa84f43e70a8c6c1d..4ea23b775e419a392b77f4d4669eb81608c9931d 100644
--- a/themes/de_105/templates/Recommend/SideFacets.phtml
+++ b/themes/de_105/templates/Recommend/SideFacets.phtml
@@ -54,7 +54,8 @@ if ($hierarchicalFacets) {
   <?php foreach ($sideFacetSet as $title => $cluster): ?>
     <div class="facet-group" id="side-panel-<?=$this->escapeHtmlAttr($title)?>">
       <?php /* use 'a' instead of 'div' below! Fix this in all instance branches to avoid validation error 'href not allowed on div'; #9416, CK */ ?>
-      <a class="title<?php if (in_array($title, $collapsedFacets)): ?> collapsed<?php endif ?>" data-toggle="collapse" href="#side-collapse-<?=$this->escapeHtmlAttr($title)?>">
+      <a <?php if (in_array($title, $collapsedFacets)): ?>class="title collapsed" aria-expanded="false"<?php else: ?>class="title" aria-expanded="true"<?php endif ?>
+        data-toggle="collapse" href="#side-collapse-<?=$this->escapeHtmlAttr($title)?>">
         <?=$this->transEsc($cluster['label'])?>
       </a>
       <ul id="side-collapse-<?=$this->escapeHtmlAttr($title)?>" class="collapse<?php if (!in_array($title, $collapsedFacets)): ?> in<?php endif ?>">