diff --git a/src/wp-includes/class-wp.php b/src/wp-includes/class-wp.php
index 44482dee0d..625dd8bdd2 100644
--- a/src/wp-includes/class-wp.php
+++ b/src/wp-includes/class-wp.php
@@ -597,7 +597,7 @@ class WP {
 		if ( is_admin() || is_robots() || $wp_query->posts ) {
 
 			// Only set X-Pingback for single posts.
-			if ( is_single() ) {
+			if ( is_singular() ) {
 				$p = get_queried_object();
 				if ( $p && pings_open( $p ) ) {
 					@header( 'X-Pingback: ' . get_bloginfo( 'pingback_url' ) );