diff --git a/lib/htmloutputter.php b/lib/htmloutputter.php
index 8f3b1a609c..5da1fbe148 100644
--- a/lib/htmloutputter.php
+++ b/lib/htmloutputter.php
@@ -113,9 +113,7 @@ class HTMLOutputter extends XMLOutputter
// Browsers don't like it when xw->startDocument('1.0', 'UTF-8');
}
- if ($doc) {
- $this->xw->writeDTD('html', $public, $system);
- }
+ $this->xw->writeDTD('html', $public, $system);
$language = $this->getLanguage();