diff --git a/wp-includes/ms-functions.php b/wp-includes/ms-functions.php
index 697da4b010..3c1911a537 100644
--- a/wp-includes/ms-functions.php
+++ b/wp-includes/ms-functions.php
@@ -161,8 +161,8 @@ function add_user_to_blog( $blog_id, $user_id, $role ) {
 
 	if ( !get_user_meta($user_id, 'primary_blog', true) ) {
 		update_user_meta($user_id, 'primary_blog', $blog_id);
-		$details = get_blog_details($blog_id);
-		update_user_meta($user_id, 'source_domain', $details->domain);
+		$site = get_site( $blog_id );
+		update_user_meta( $user_id, 'source_domain', $site->domain );
 	}
 
 	$user->set_role($role);
diff --git a/wp-includes/version.php b/wp-includes/version.php
index eb78c437bf..6830c52099 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.7-alpha-38902';
+$wp_version = '4.7-alpha-38903';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.