diff --git a/wp-includes/functions.php b/wp-includes/functions.php
index 87eef314ca..56a444b0f2 100644
--- a/wp-includes/functions.php
+++ b/wp-includes/functions.php
@@ -4423,7 +4423,7 @@ function is_main_site( $site_id = null, $network_id = null ) {
  */
 function get_main_site_id( $network_id = null ) {
 	if ( ! is_multisite() ) {
-		return 1;
+		return get_current_blog_id();
 	}
 
 	$network = get_network( $network_id );
diff --git a/wp-includes/version.php b/wp-includes/version.php
index d634272de2..c6c314a537 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.9-beta2-41861';
+$wp_version = '4.9-beta2-41862';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.