--- a/util/filters.lua	Mon Aug 10 22:16:05 2015 +0200
+++ b/util/filters.lua	Sat Feb 21 10:36:37 2015 +0100
@@ -8,11 +8,11 @@
 
 local t_insert, t_remove = table.insert, table.remove;
 
-module "filters"
+local _ENV = nil;
 
 local new_filter_hooks = {};
 
-function initialize(session)
+local function initialize(session)
 	if not session.filters then
 		local filters = {};
 		session.filters = filters;
@@ -36,7 +36,7 @@
 	return session.filter;
 end
 
-function add_filter(session, type, callback, priority)
+local function add_filter(session, type, callback, priority)
 	if not session.filters then
 		initialize(session);
 	end
@@ -60,7 +60,7 @@
 	filter_list[callback] = priority;
 end
 
-function remove_filter(session, type, callback)
+local function remove_filter(session, type, callback)
 	if not session.filters then return; end
 	local filter_list = session.filters[type];
 	if filter_list and filter_list[callback] then
@@ -74,11 +74,11 @@
 	end
 end
 
-function add_filter_hook(callback)
+local function add_filter_hook(callback)
 	t_insert(new_filter_hooks, callback);
 end
 
-function remove_filter_hook(callback)
+local function remove_filter_hook(callback)
 	for i=1,#new_filter_hooks do
 		if new_filter_hooks[i] == callback then
 			t_remove(new_filter_hooks, i);
@@ -86,4 +86,10 @@
 	end
 end
 
-return _M;
+return {
+	initialize = initialize;
+	add_filter = add_filter;
+	remove_filter = remove_filter;
+	add_filter_hook = add_filter_hook;
+	remove_filter_hook = remove_filter_hook;
+};