diff -u b/core/modules/system/templates/admin-block.html.twig b/core/modules/system/templates/admin-block.html.twig
--- b/core/modules/system/templates/admin-block.html.twig
+++ b/core/modules/system/templates/admin-block.html.twig
@@ -20,7 +20,7 @@
   {% endif %}
   {% if block.content %}
-    <div class="body admin-panel__body">{{ block.content }}</div>
+    <div class="admin-panel__body">{{ block.content }}</div>
   {% elseif block.description %}
-    <div class="description admin-panel__description">{{ block.description }}</div>
+    <div class="admin-panel__description">{{ block.description }}</div>
   {% endif %}
 </div>