diff --git a/core/modules/file/src/Element/ManagedFile.php b/core/modules/file/src/Element/ManagedFile.php
index bcc5011..1f88501 100644
--- a/core/modules/file/src/Element/ManagedFile.php
+++ b/core/modules/file/src/Element/ManagedFile.php
@@ -181,7 +181,8 @@ public static function uploadAjaxCallback(&$form, FormStateInterface &$form_stat
     // Add the special AJAX class if a new file was added.
     $current_file_count = $form_state->get('file_upload_delta_initial');
     if (isset($form['#file_upload_delta']) && $current_file_count < $form['#file_upload_delta']) {
-      $form[$current_file_count]['#attributes']['class'][] = 'ajax-new-content managed-file';
+      $form[$current_file_count]['#attributes']['class'][] = 'ajax-new-content';
+      $form[$current_file_count]['#attributes']['class'][] = 'managed-file';
     }
     // Otherwise just add the new content class on a placeholder.
     else {