diff --git a/sites/all/themes/unl_wdn/html.tpl.php b/sites/all/themes/unl_wdn/html.tpl.php
index 6a19b76377574f242aed8d171f811bd5ed554db5..0db456ad9c49ac6230744fdae472f2c91764702e 100644
--- a/sites/all/themes/unl_wdn/html.tpl.php
+++ b/sites/all/themes/unl_wdn/html.tpl.php
@@ -52,11 +52,18 @@ $t->doctitle = '<title>'.$head_title.'</title>';
$html = $t->toHtml();
-$html = strtr($html, array('<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">' => '<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="'.$language->language.'" version="XHTML+RDFa 1.0" dir="'.$language->dir.'" '.$rdf_namespaces.'>',
- '<head>' => '<head profile="'.$grddl_profile.'">',
- '<body class="fixed">' => '<body class="fixed '.$classes.'" '.$attributes.'>',
- '<p class="skipnav">' => $page_top . PHP_EOL . '<p class="skipnav">',
- '</body>' => $page_bottom . PHP_EOL . '</body>',
- ));
+if (module_exists('rdf')) {
+ $html = strtr($html, array(
+ '<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">' => '<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="'.$language->language.'" version="XHTML+RDFa 1.0" dir="'.$language->dir.'" '.$rdf_namespaces.'>',
+ '<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">' => '<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML+RDFa 1.0//EN" "http://www.w3.org/MarkUp/DTD/xhtml-rdfa-1.dtd">',
+ '<head>' => '<head profile="'.$grddl_profile.'">',
+ ));
+}
+
+$html = strtr($html, array(
+ '<body class="fixed">' => '<body class="fixed '.$classes.'" '.$attributes.'>',
+ '<p class="skipnav">' => $page_top . PHP_EOL . '<p class="skipnav">',
+ '</body>' => $page_bottom . PHP_EOL . '</body>',
+));
echo $html;