diff --git a/src/wp-includes/comment.php b/src/wp-includes/comment.php
index de23a72130..37d36364ce 100644
--- a/src/wp-includes/comment.php
+++ b/src/wp-includes/comment.php
@@ -3174,10 +3174,10 @@ function privacy_ping_filter( $sites ) {
  * @param string $trackback_url URL to send trackbacks.
  * @param string $title         Title of post.
  * @param string $excerpt       Excerpt of post.
- * @param int    $ID            Post ID.
+ * @param int    $post_id       Post ID.
  * @return int|false|void Database query from update.
  */
-function trackback( $trackback_url, $title, $excerpt, $ID ) {
+function trackback( $trackback_url, $title, $excerpt, $post_id ) {
 	global $wpdb;
 
 	if ( empty( $trackback_url ) ) {
@@ -3188,7 +3188,7 @@ function trackback( $trackback_url, $title, $excerpt, $ID ) {
 	$options['timeout'] = 10;
 	$options['body']    = array(
 		'title'     => $title,
-		'url'       => get_permalink( $ID ),
+		'url'       => get_permalink( $post_id ),
 		'blog_name' => get_option( 'blogname' ),
 		'excerpt'   => $excerpt,
 	);
@@ -3199,8 +3199,8 @@ function trackback( $trackback_url, $title, $excerpt, $ID ) {
 		return;
 	}
 
-	$wpdb->query( $wpdb->prepare( "UPDATE $wpdb->posts SET pinged = CONCAT(pinged, '\n', %s) WHERE ID = %d", $trackback_url, $ID ) );
-	return $wpdb->query( $wpdb->prepare( "UPDATE $wpdb->posts SET to_ping = TRIM(REPLACE(to_ping, %s, '')) WHERE ID = %d", $trackback_url, $ID ) );
+	$wpdb->query( $wpdb->prepare( "UPDATE $wpdb->posts SET pinged = CONCAT(pinged, '\n', %s) WHERE ID = %d", $trackback_url, $post_id ) );
+	return $wpdb->query( $wpdb->prepare( "UPDATE $wpdb->posts SET to_ping = TRIM(REPLACE(to_ping, %s, '')) WHERE ID = %d", $trackback_url, $post_id ) );
 }
 
 /**