diff --git a/include/class.format.php b/include/class.format.php
index 5146c251e6b46e8d79ddab178b5480d611780342..539bf5f51d5cdc43565d6806f02a8e96a19611d3 100644
--- a/include/class.format.php
+++ b/include/class.format.php
@@ -207,8 +207,10 @@ class Format {
// Remove HEAD and STYLE sections
$html = preg_replace(
array(':<(head|style).+</\1>:is', # <head> and <style> sections
- ':<!\[[^]<]+\]>:'), # <![if !mso]> and friends
- array('', ''),
+ ':<!\[[^]<]+\]>:', # <![if !mso]> and friends
+ ':<!DOCTYPE[^>]+>:', # <!DOCTYPE ... >
+ ),
+ array('', '', ''),
$html);
$config = array(
'safe' => 1, //Exclude applet, embed, iframe, object and script tags.