diff --git a/inc/templates/header.php b/inc/templates/header.php
index dbff30d89041f2e143a2f6e08440fb9c60c46bd8..e28fa4da9fb5fa014c9edb970148011d1a107851 100755
--- a/inc/templates/header.php
+++ b/inc/templates/header.php
@@ -1,6 +1,7 @@
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
-<html><head>
+<html xmlns="http://www.w3.org/1999/xhtml">
+<head>
<title>ownCloud</title>
<link rel="stylesheet" type="text/css" href="/css/default.css" />
</head>