diff --git a/wp-includes/class-wp-block-patterns-registry.php b/wp-includes/class-wp-block-patterns-registry.php
index d1ef2ad422..e516277e42 100644
--- a/wp-includes/class-wp-block-patterns-registry.php
+++ b/wp-includes/class-wp-block-patterns-registry.php
@@ -164,12 +164,15 @@ final class WP_Block_Patterns_Registry {
 	 */
 	private function prepare_content( $pattern, $hooked_blocks ) {
 		$content = $pattern['content'];
+
+		$before_block_visitor = '_inject_theme_attribute_in_template_part_block';
+		$after_block_visitor  = null;
 		if ( ! empty( $hooked_blocks ) || has_filter( 'hooked_block_types' ) ) {
-			$blocks               = parse_blocks( $content );
 			$before_block_visitor = make_before_block_visitor( $hooked_blocks, $pattern );
 			$after_block_visitor  = make_after_block_visitor( $hooked_blocks, $pattern );
-			$content              = traverse_and_serialize_blocks( $blocks, $before_block_visitor, $after_block_visitor );
 		}
+		$blocks  = parse_blocks( $content );
+		$content = traverse_and_serialize_blocks( $blocks, $before_block_visitor, $after_block_visitor );
 
 		return $content;
 	}
diff --git a/wp-includes/version.php b/wp-includes/version.php
index aa4d904018..f4fc6ae597 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.4-beta2-56817';
+$wp_version = '6.4-beta2-56818';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.