diff --git a/wp-includes/general-template.php b/wp-includes/general-template.php
index 915aea540e..e694e2cb30 100644
--- a/wp-includes/general-template.php
+++ b/wp-includes/general-template.php
@@ -703,7 +703,7 @@ function get_bloginfo( $show = '', $filter = 'raw' ) {
 			 */
 			$output = __( 'html_lang_attribute' );
 			if ( 'html_lang_attribute' === $output || preg_match( '/[^a-zA-Z0-9-]/', $output ) ) {
-				$output = get_locale();
+				$output = is_admin() ? get_user_locale() : get_locale();
 				$output = str_replace( '_', '-', $output );
 			}
 			break;
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 4f31a3110c..bac97f4b3b 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.0-alpha-42218';
+$wp_version = '5.0-alpha-42220';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.