diff --git a/nether/portal.lua b/nether/portal.lua
index 2a5c2ba..ffbb47d 100644
--- a/nether/portal.lua
+++ b/nether/portal.lua
@@ -238,7 +238,7 @@ if nether_prisons then
 	-- set background when player joins
 	minetest.register_on_joinplayer(function(player)
 		minetest.after(0, function(player)
-			if player:getpos().y < nether.start then
+			if player and player:getpos() and player:getpos().y < nether.start then
 				update_background(player, true)
 			end
 		end, player)