diff --git a/core/modules/comment/src/CommentStorageInterface.php b/core/modules/comment/src/CommentStorageInterface.php
index 06b99a9..337d5fa 100644
--- a/core/modules/comment/src/CommentStorageInterface.php
+++ b/core/modules/comment/src/CommentStorageInterface.php
@@ -51,7 +51,7 @@ public function getMaxThreadPerThread(CommentInterface $comment);
    *   The field name on the entity to which comments are attached.
    *
    * @return array|null
-   *   Page number where first new comment appears.
+   *   The page number where first new comment appears. (First page returns 0.)
    */
   public function getNewCommentPageNumber($total_comments, $new_comments, ContentEntityInterface $entity, $field_name = 'comment');