diff --git a/web/skins/bootstrap/includes/functions.php b/web/skins/bootstrap/includes/functions.php
index 50898a07a..2b50bfc71 100644
--- a/web/skins/bootstrap/includes/functions.php
+++ b/web/skins/bootstrap/includes/functions.php
@@ -36,8 +36,8 @@ function xhtmlHeaders( $file, $title )
 
     extract( $GLOBALS, EXTR_OVERWRITE );
 ?>
-<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
-<html xmlns="http://www.w3.org/1999/xhtml">
+<!DOCTYPE html>
+<html lang="en">
 <head>
   <title><?= ZM_WEB_TITLE_PREFIX ?> - <?= validHtmlStr($title) ?></title>
   <link rel="icon" type="image/ico" href="graphics/favicon.ico"/>
