diff --git a/src/wp-includes/admin-bar.php b/src/wp-includes/admin-bar.php
index 49279a9926..9e75de5d13 100644
--- a/src/wp-includes/admin-bar.php
+++ b/src/wp-includes/admin-bar.php
@@ -22,7 +22,7 @@ function _wp_admin_bar_init() {
 		return false;
 
 	/* Load the admin bar class code ready for instantiation */
-	require( ABSPATH . WPINC . '/class-wp-admin-bar.php' );
+	require_once( ABSPATH . WPINC . '/class-wp-admin-bar.php' );
 
 	/* Instantiate the admin bar */