diff --git a/lib/compat/wordpress-5.9/class-wp-rest-global-styles-controller.php b/lib/compat/wordpress-5.9/class-wp-rest-global-styles-controller.php
index 5e7be742b86db..e4171c7eb0872 100644
--- a/lib/compat/wordpress-5.9/class-wp-rest-global-styles-controller.php
+++ b/lib/compat/wordpress-5.9/class-wp-rest-global-styles-controller.php
@@ -277,7 +277,7 @@ protected function prepare_item_for_database( $request ) {
 					$config['settings'] = $existing_config['settings'];
 				}
 				$config['isGlobalStylesUserThemeJSON'] = true;
-				$config['version']                     = WP_Theme_JSON::LATEST_SCHEMA;
+				$config['version']                     = WP_Theme_JSON_Gutenberg::LATEST_SCHEMA;
 				$changes->post_content                 = wp_json_encode( $config );
 			}
 
@@ -307,7 +307,7 @@ public function prepare_item_for_response( $post, $request ) { // phpcs:ignore V
 			$is_global_styles_user_theme_json = isset( $raw_config['isGlobalStylesUserThemeJSON'] ) && true === $raw_config['isGlobalStylesUserThemeJSON'];
 			$config                           = array();
 			if ( $is_global_styles_user_theme_json ) {
-				$config = ( new WP_Theme_JSON( $raw_config, 'custom' ) )->get_raw_data();
+				$config = ( new WP_Theme_JSON_Gutenberg( $raw_config, 'custom' ) )->get_raw_data();
 			}
 
 			// Base fields for every post.
@@ -555,7 +555,7 @@ public function get_theme_item( $request ) {
 				);
 			}
 
-			$theme  = WP_Theme_JSON_Resolver::get_merged_data( 'theme' );
+			$theme  = WP_Theme_JSON_Resolver_Gutenberg::get_merged_data( 'theme' );
 			$data   = array();
 			$fields = $this->get_fields_for_response( $request );