diff --git src/wp-includes/query.php src/wp-includes/query.php
index 693019f659..5c61004c09 100644
--- src/wp-includes/query.php
+++ src/wp-includes/query.php
@@ -982,7 +982,7 @@ function wp_old_slug_redirect() {
 		 *
 		 * @since 4.9.3
 		 *
-		 * @param string $id The redirect post ID.
+		 * @param int $id The redirect post ID.
 		 */
 		$id = apply_filters( 'old_slug_redirect_post_id', $id );
 
@@ -1064,7 +1064,6 @@ function _find_post_by_old_slug( $post_type ) {
  * @param string $post_type The current post type based on the query vars.
  * @return int $id The Post ID.
  */
-
 function _find_post_by_old_date( $post_type ) {
 	global $wpdb;