diff --git a/wp-includes/admin-bar.php b/wp-includes/admin-bar.php
index 07c348dbb..e9a9b0e39 100644
--- a/wp-includes/admin-bar.php
+++ b/wp-includes/admin-bar.php
@@ -516,7 +516,7 @@ function wp_admin_bar_comments_menu( $wp_admin_bar ) {
 
 	$awaiting_mod = wp_count_comments();
 	$awaiting_mod = $awaiting_mod->moderated;
-	$awaiting_title = sprintf( _n( '%s comment awaiting moderation', '%s comments awaiting moderation', $awaiting_mod ), number_format_i18n( $awaiting_mod ) );
+	$awaiting_title = esc_attr( sprintf( _n( '%s comment awaiting moderation', '%s comments awaiting moderation', $awaiting_mod ), number_format_i18n( $awaiting_mod ) ) );
 
 	$icon  = "<div class='ab-comments-icon' title='$awaiting_title'>";
 	$icon .= "<div class='ab-comments-icon-body'></div>";