diff --git a/core/modules/file/file.module b/core/modules/file/file.module
index ee12a41..9220fe7 100644
--- a/core/modules/file/file.module
+++ b/core/modules/file/file.module
@@ -1192,6 +1192,7 @@ function template_preprocess_file_managed_file(&$variables) {
   if (!empty($element['#attributes']['class'])) {
     $variables['attributes']['class'] = (array) $element['#attributes']['class'];
   }
+  $variables['attributes']['class'][] = 'form-managed-file';
 }
 
 /**
diff --git a/core/themes/classy/templates/content-edit/file-managed-file.html.twig b/core/themes/classy/templates/content-edit/file-managed-file.html.twig
index 43739be..d7b9120 100644
--- a/core/themes/classy/templates/content-edit/file-managed-file.html.twig
+++ b/core/themes/classy/templates/content-edit/file-managed-file.html.twig
@@ -10,6 +10,6 @@
  * @see template_preprocess_file_managed_file()
  */
 #}
-<div{{ attributes.addClass('form-managed-file') }}>
+<div{{ attributes }}>
   {{ element }}
 </div>