diff --git a/core/modules/comment/comment.module b/core/modules/comment/comment.module
index 7d22dde..0ee6f4c 100644
--- a/core/modules/comment/comment.module
+++ b/core/modules/comment/comment.module
@@ -699,7 +699,6 @@ function template_preprocess_comment(&$variables) {
   );
   $variables['author'] = drupal_render($username);
   $variables['author_id'] = $comment->getOwnerId();
-  $variables['author_is_anonymous'] = $comment->getOwner()->isAnonymous();
   $variables['new_indicator_timestamp'] = $comment->getChangedTime();
   $variables['created'] = format_date($comment->getCreatedTime());
   // Avoid calling format_date() twice on the same timestamp.
diff --git a/core/modules/comment/templates/comment.html.twig b/core/modules/comment/templates/comment.html.twig
index 07bc3b1..27b3296 100644
--- a/core/modules/comment/templates/comment.html.twig
+++ b/core/modules/comment/templates/comment.html.twig
@@ -5,8 +5,6 @@
  *
  * Available variables:
  * - author: Comment author. Can be a link or plain text.
- * - author_is_anonymous: A flag indicating if the comment was submitted
- *   anonymously.
  * - content: The content-related items for the comment display. Use
  *   {{ content }} to print them all, or print a subset such as
  *   {{ content.field_example }}. Use the following code to temporarily suppress
@@ -72,7 +70,7 @@
   set classes = [
     'comment',
     status != 'published' ? status,
-    author_is_anonymous ? 'by-anonymous',
+    comment.getOwner().isAnonymous() ? 'by-anonymous',
     author_id and author_id == commented_entity.getOwnerId() ? 'by-' ~ commented_entity.getEntityTypeId() ~ '-author',
     'clearfix',
   ]
diff --git a/core/themes/bartik/templates/comment.html.twig b/core/themes/bartik/templates/comment.html.twig
index acbffb2..bf43ebc 100644
--- a/core/themes/bartik/templates/comment.html.twig
+++ b/core/themes/bartik/templates/comment.html.twig
@@ -5,8 +5,6 @@
  *
  * Available variables:
  * - author: Comment author. Can be a link or plain text.
- * - author_is_anonymous: A flag indicating if the comment was submitted
- *   anonymously.
  * - content: The content-related items for the comment display. Use
  *   {{ content }} to print them all, or print a subset such as
  *   {{ content.field_example }}. Use the following code to temporarily suppress
@@ -70,7 +68,7 @@
   set classes = [
     'comment',
     status != 'published' ? status,
-    author_is_anonymous ? 'by-anonymous',
+    comment.getOwner().isAnonymous() ? 'by-anonymous',
     author_id and author_id == commented_entity.getOwnerId() ? 'by-' ~ commented_entity.getEntityTypeId() ~ '-author',
     'clearfix',
   ]