diff --git a/phpBB/privmsg.php b/phpBB/privmsg.php
index f310d8253a..e69e8ab716 100644
--- a/phpBB/privmsg.php
+++ b/phpBB/privmsg.php
@@ -1187,7 +1187,7 @@ else if ( $submit || $refresh || $mode != '' )
 			$error_msg .= ( ( !empty($error_msg) ) ? '<br />' : '' ) . $lang['No_to_user'];
 		}
 
-		$privmsg_subject = trim(strip_tags($HTTP_POST_VARS['subject']));
+		$privmsg_subject = trim(htmlspecialchars($HTTP_POST_VARS['subject']));
 		if ( empty($privmsg_subject) )
 		{
 			$error = TRUE;
@@ -1374,7 +1374,7 @@ else if ( $submit || $refresh || $mode != '' )
 		//
 		$to_username = (isset($HTTP_POST_VARS['username']) ) ? trim(htmlspecialchars(stripslashes($HTTP_POST_VARS['username']))) : '';
 
-		$privmsg_subject = ( isset($HTTP_POST_VARS['subject']) ) ? trim(strip_tags(stripslashes($HTTP_POST_VARS['subject']))) : '';
+		$privmsg_subject = ( isset($HTTP_POST_VARS['subject']) ) ? trim(htmlspecialchars(stripslashes($HTTP_POST_VARS['subject']))) : '';
 		$privmsg_message = ( isset($HTTP_POST_VARS['message']) ) ? trim($HTTP_POST_VARS['message']) : '';
 		$privmsg_message = preg_replace('#<textarea>#si', '&lt;textarea&gt;', $privmsg_message);
 		if ( !$preview )