diff --git a/hud.lua b/hud.lua
index bb07ca2..462bad1 100644
--- a/hud.lua
+++ b/hud.lua
@@ -33,7 +33,7 @@ minetest.register_on_leaveplayer(function(player)
 end)
 
 
-mail.hud_update = function(playername, messages)
+function mail.hud_update(playername, messages)
 	local data = huddata[playername]
 	local player = minetest.get_player_by_name(playername)
 
diff --git a/migrate.lua b/migrate.lua
index 7107606..1cefbd7 100644
--- a/migrate.lua
+++ b/migrate.lua
@@ -1,7 +1,7 @@
 
 -- migrate from mail.db to player-file-based mailbox
 
-mail.migrate = function()
+function mail.migrate()
 	-- create directory, just in case
 	minetest.mkdir(mail.maildir)
 	minetest.mkdir(mail.contactsdir)
@@ -26,7 +26,7 @@ mail.migrate = function()
 end
 
 
-mail.migrate_contacts = function(playername)
+function mail.migrate_contacts(playername)
 	local file = io.open(mail.getContactsFile(playername), 'r')
 	if not file then
 		-- file doesn't exist! This is a case for Migrate Man!
diff --git a/storage.lua b/storage.lua
index d70ee4b..daa3c7c 100644
--- a/storage.lua
+++ b/storage.lua
@@ -10,7 +10,7 @@ function mail.getContactsFile(playername)
 end
 
 
-mail.getMessages = function(playername)
+function mail.getMessages(playername)
 	local messages = mail.read_json_file(mail.getMailFile(playername))
 	if messages then
 		-- sort by received date descending
@@ -22,7 +22,7 @@ mail.getMessages = function(playername)
 	return messages
 end
 
-mail.setMessages = function(playername, messages)
+function mail.setMessages(playername, messages)
 	if mail.write_json_file(mail.getMailFile(playername), messages) then
 		mail.hud_update(playername, messages)
 		return true
@@ -33,7 +33,7 @@ mail.setMessages = function(playername, messages)
 end
 
 
-mail.getContacts = function(playername)
+function mail.getContacts(playername)
 	return mail.read_json_file(mail.getContactsFile(playername))
 end
 
@@ -56,7 +56,7 @@ function mail.pairsByKeys(t, f)
 	return iter
 end
 
-mail.setContacts = function(playername, contacts)
+function mail.setContacts(playername, contacts)
 	if mail.write_json_file(mail.getContactsFile(playername), contacts) then
 		return true
 	else