diff --git a/src/wp-includes/meta.php b/src/wp-includes/meta.php
index 6b361aaa5e..921c24c383 100644
--- a/src/wp-includes/meta.php
+++ b/src/wp-includes/meta.php
@@ -1214,6 +1214,9 @@ function wp_metadata_lazyloader() {
 	static $wp_metadata_lazyloader;
 
 	if ( null === $wp_metadata_lazyloader ) {
+		if ( ! class_exists( 'WP_Metadata_Lazyloader' ) ) {
+			require_once ABSPATH . WPINC . '/class-wp-metadata-lazyloader.php';
+		}
 		$wp_metadata_lazyloader = new WP_Metadata_Lazyloader();
 	}