diff --git a/src/wp-includes/link-template.php b/src/wp-includes/link-template.php
index de9988be1f..533a7daf6c 100644
--- a/src/wp-includes/link-template.php
+++ b/src/wp-includes/link-template.php
@@ -2318,11 +2318,11 @@ function get_adjacent_post_link( $format, $link, $in_same_term = false, $exclude
 	 * @since 2.6.0
 	 * @since 4.2.0 Added the `$adjacent` parameter.
 	 *
-	 * @param string  $output   The adjacent post link.
-	 * @param string  $format   Link anchor format.
-	 * @param string  $link     Link permalink format.
-	 * @param WP_Post $post     The adjacent post.
-	 * @param string  $adjacent Whether the post is previous or next.
+	 * @param string         $output   The adjacent post link.
+	 * @param string         $format   Link anchor format.
+	 * @param string         $link     Link permalink format.
+	 * @param WP_Post|string $post     The adjacent post. Empty string if no corresponding post exists.
+	 * @param string         $adjacent Whether the post is previous or next.
 	 */
 	return apply_filters( "{$adjacent}_post_link", $output, $format, $link, $post, $adjacent );
 }