diff --git a/includes/class-create-block-theme-editor-tools.php b/includes/class-create-block-theme-editor-tools.php
index 4a940cda..a88d18af 100644
--- a/includes/class-create-block-theme-editor-tools.php
+++ b/includes/class-create-block-theme-editor-tools.php
@@ -16,7 +16,7 @@ public function __construct() {
 	function create_block_theme_sidebar_enqueue() {
 		global $pagenow;
 
-		if ( 'site-editor.php' !== $pagenow ) {
+		if ( 'site-editor.php' !== $pagenow || ! wp_is_block_theme() ) {
 			return;
 		}