diff --git a/src/wp-includes/class-wp-customize-manager.php b/src/wp-includes/class-wp-customize-manager.php
index 51c88ef5fcf81..5f24d96a54cca 100644
--- a/src/wp-includes/class-wp-customize-manager.php
+++ b/src/wp-includes/class-wp-customize-manager.php
@@ -286,13 +286,8 @@ public function __construct( $args = array() ) {
 			$args['messenger_channel'] = sanitize_key( wp_unslash( $_REQUEST['customize_messenger_channel'] ) );
 		}
 
-		// Do not load 'widgets' component if a block theme is activated.
-		if ( ! wp_is_block_theme() ) {
-			$this->components[] = 'widgets';
-		}
-
 		$this->original_stylesheet = get_stylesheet();
-		$this->theme               = wp_get_theme( 0 === validate_file( $args['theme'] ) ? $args['theme'] : null );
+		$this->theme               = 0 === validate_file( $args['theme'] ) ? $args['theme'] : null;
 		$this->messenger_channel   = $args['messenger_channel'];
 		$this->_changeset_uuid     = $args['changeset_uuid'];
 
@@ -515,6 +510,14 @@ public function wp_die_handler() {
 	public function setup_theme() {
 		global $pagenow;
 
+		// Do not load 'widgets' component if a block theme is activated.
+		if ( ! wp_is_block_theme() ) {
+			$this->components[] = 'widgets';
+		}
+
+		// Use the theme value stored during instantiation to get the WP_Theme object.
+		$this->theme = wp_get_theme( $this->theme );
+
 		// Check permissions for customize.php access since this method is called before customize.php can run any code.
 		if ( 'customize.php' === $pagenow && ! current_user_can( 'customize' ) ) {
 			if ( ! is_user_logged_in() ) {