diff --git a/admin-dev/themes/default/template/header.tpl b/admin-dev/themes/default/template/header.tpl
index 564be4338..6a1113b6a 100644
--- a/admin-dev/themes/default/template/header.tpl
+++ b/admin-dev/themes/default/template/header.tpl
@@ -26,7 +26,7 @@
 <!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" xml:lang="{$iso}" lang="{$iso}">
 	<head>
-		<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
+		<meta http-equiv="Content-Type" content="application/xhtml+xml; charset=utf-8" />
 		<meta name="robots" content="NOFOLLOW, NOINDEX" />
 		<title>{$meta_title} - PrestaShop&trade;</title>
 		{if $display_header}
