diff --git a/modules/book/book-export-html.tpl.php b/modules/book/book-export-html.tpl.php
index 4b25a76..e903bb5 100644
--- a/core/modules/book/book-export-html.tpl.php
+++ b/core/modules/book/book-export-html.tpl.php
@@ -16,8 +16,8 @@
  * @see template_preprocess_book_export_html()
  */
 ?>
-<!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" lang="<?php print $language->language; ?>" xml:lang="<?php print $language->language; ?>">
+<!DOCTYPE html >
+<html<?php print $html_attributes; ?>>
   <head>
     <title><?php print $title; ?></title>
     <?php print $head; ?>

