diff --git a/mods/CORE/mcl_worlds/init.lua b/mods/CORE/mcl_worlds/init.lua
index 4f8914506..7feab7317 100644
--- a/mods/CORE/mcl_worlds/init.lua
+++ b/mods/CORE/mcl_worlds/init.lua
@@ -118,11 +118,10 @@ local last_dimension = {}
 -- * player: Player who changed the dimension
 -- * dimension: New dimension ("overworld", "nether", "end", "void")
 function mcl_worlds.dimension_change(player, dimension)
-	local playername = player:get_player_name()
 	for i=1, #mcl_worlds.registered_on_dimension_change do
-		mcl_worlds.registered_on_dimension_change[i](player, dimension, last_dimension[playername])
+		mcl_worlds.registered_on_dimension_change[i](player, dimension, last_dimension[player])
 	end
-	last_dimension[playername] = dimension
+	last_dimension[player] = dimension
 end
 
 local dimension_change = mcl_worlds.dimension_change
@@ -134,19 +133,21 @@ local DIM_UPDATE = 1
 local dimtimer = 0
 
 minetest.register_on_joinplayer(function(player)
-	last_dimension[player:get_player_name()] = pos_to_dimension(player:get_pos())
+	last_dimension[player] = pos_to_dimension(player:get_pos())
+end)
+
+minetest.regsister_on_leaveplayer(function(player)
+	last_dimension[player] = nil
 end)
 
 minetest.register_globalstep(function(dtime)
 	-- regular updates based on iterval
-	dimtimer = dimtimer + dtime;
+	dimtimer = dimtimer + dtime
 	if dimtimer >= DIM_UPDATE then
-		local players = get_connected_players()
-		for p = 1, #players do
-			local dim = pos_to_dimension(players[p]:get_pos())
-			local name = players[p]:get_player_name()
-			if dim ~= last_dimension[name] then
-				dimension_change(players[p], dim)
+		for _, player in pairs(get_connected_players()) do
+			local dim = pos_to_dimension(player:get_pos())
+			if dim ~= last_dimension[player] then
+				dimension_change(player, dim)
 			end
 		end
 		dimtimer = 0