diff --git a/src/wp-includes/block-editor.php b/src/wp-includes/block-editor.php
index b42c0c09f0..476d89e984 100644
--- a/src/wp-includes/block-editor.php
+++ b/src/wp-includes/block-editor.php
@@ -418,7 +418,7 @@ function get_block_editor_settings( array $custom_settings, $block_editor_contex
 		 * Add the custom CSS as a separate stylesheet so any invalid CSS
 		 * entered by users does not break other global styles.
 		 */
-		$editor_settings['styles'][] = array(
+		$global_styles[] = array(
 			'css'            => wp_get_global_styles_custom_css(),
 			'__unstableType' => 'user',
 			'isGlobalStyles' => true,