diff --git a/phpBB/includes/functions.php b/phpBB/includes/functions.php
index 35eea291dc..8c29bc7171 100644
--- a/phpBB/includes/functions.php
+++ b/phpBB/includes/functions.php
@@ -5046,6 +5046,22 @@ function page_header($page_title = '', $display_online_list = false, $item_id =
 		'SITE_LOGO_IMG'			=> $user->img('site_logo'),
 	));
 
+	/**
+	* Execute code and/or overwrite _common_ template variables after they have been assigned.
+	*
+	* @event core.page_header_after
+	* @var	string	page_title			Page title
+	* @var	bool	display_online_list		Do we display online users list
+	* @var	string	item				Restrict online users to a certain
+	*									session item, e.g. forum for
+	*									session_forum_id
+	* @var	int		item_id				Restrict online users to item id
+	*
+	* @since 3.1.0-b3
+	*/
+	$vars = array('page_title', 'display_online_list', 'item_id', 'item');
+	extract($phpbb_dispatcher->trigger_event('core.page_header_after', compact($vars)));
+
 	// application/xhtml+xml not used because of IE
 	header('Content-type: text/html; charset=UTF-8');