diff --git a/core/themes/classy/templates/form/details.html.twig b/core/themes/classy/templates/form/details.html.twig
index 9b149d7..46d8dd0 100644
--- a/core/themes/classy/templates/form/details.html.twig
+++ b/core/themes/classy/templates/form/details.html.twig
@@ -5,6 +5,7 @@
  *
  * Available variables
  * - attributes: A list of HTML attributes for the details element.
+ * - errors: (optional) Any errors for this details element, may not be set.
  * - title: (optional) The title of the element, may not be set.
  * - description: (optional) The description of the element, may not be set.
  * - children: (optional) The children of the element, may not be set.
@@ -18,6 +19,11 @@
     <summary{{ summary_attributes }}>{{ title }}</summary>
   {%- endif -%}
   <div class="details-wrapper">
+    {% if errors %}
+      <div class="form-error-message">
+        <strong>{{ errors }}</strong>
+      </div>
+    {% endif %}
     {%- if description -%}
       <div class="details-description">{{ description }}</div>
     {%- endif -%}