diff --git a/wp-includes/rest-api/endpoints/class-wp-rest-global-styles-controller.php b/wp-includes/rest-api/endpoints/class-wp-rest-global-styles-controller.php
index d9ff86e1fa..e6771ff851 100644
--- a/wp-includes/rest-api/endpoints/class-wp-rest-global-styles-controller.php
+++ b/wp-includes/rest-api/endpoints/class-wp-rest-global-styles-controller.php
@@ -563,7 +563,10 @@ class WP_REST_Global_Styles_Controller extends WP_REST_Controller {
 		}
 
 		if ( rest_is_field_included( 'styles', $fields ) ) {
-			$data['styles'] = $theme->get_raw_data()['styles'];
+			$raw_data = $theme->get_raw_data();
+			if ( isset( $raw_data['styles'] ) ) {
+				$data['styles'] = $raw_data['styles'];
+			}
 		}
 
 		$context = ! empty( $request['context'] ) ? $request['context'] : 'view';
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 14d56ac2b0..3da121199a 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.0-alpha-52749';
+$wp_version = '6.0-alpha-52750';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.