diff --git a/src/wp-includes/functions.php b/src/wp-includes/functions.php
index 0e0f626e56..8923cc23f3 100644
--- a/src/wp-includes/functions.php
+++ b/src/wp-includes/functions.php
@@ -5226,6 +5226,7 @@ function wp_maybe_load_widgets() {
  * Append the Widgets menu to the themes main menu.
  *
  * @since 2.2.0
+ * @since 5.9.3 Don't specify menu order when the active theme is a block theme.
  *
  * @global array $submenu
  */
@@ -5236,7 +5237,13 @@ function wp_widgets_add_menu() {
 		return;
 	}
 
-	$submenu['themes.php'][7] = array( __( 'Widgets' ), 'edit_theme_options', 'widgets.php' );
+	$menu_name = __( 'Widgets' );
+	if ( wp_is_block_theme() ) {
+		$submenu['themes.php'][] = array( $menu_name, 'edit_theme_options', 'widgets.php' );
+	} else {
+		$submenu['themes.php'][7] = array( $menu_name, 'edit_theme_options', 'widgets.php' );
+	}
+
 	ksort( $submenu['themes.php'], SORT_NUMERIC );
 }