diff --git a/wp-includes/class-wp.php b/wp-includes/class-wp.php
index 44482dee0d..625dd8bdd2 100644
--- a/wp-includes/class-wp.php
+++ b/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' ) );
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 6b7b9e904c..1d5b24dcff 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.4-alpha-34442';
+$wp_version = '4.4-alpha-34443';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.