diff --git a/src/wp-includes/ms-blogs.php b/src/wp-includes/ms-blogs.php
index 0be865fd87..216cf56fe0 100644
--- a/src/wp-includes/ms-blogs.php
+++ b/src/wp-includes/ms-blogs.php
@@ -696,6 +696,9 @@ function restore_current_blog() {
  * @param int $old_site_id Old site ID.
  */
 function wp_switch_roles_and_user( $new_site_id, $old_site_id ) {
+	$new_site_id = (int) $new_site_id;
+	$old_site_id = (int) $old_site_id;
+
 	if ( $new_site_id === $old_site_id ) {
 		return;
 	}