diff --git a/mods/boxes/nodes.lua b/mods/boxes/nodes.lua
index fb40f7c..41aca88 100644
--- a/mods/boxes/nodes.lua
+++ b/mods/boxes/nodes.lua
@@ -434,7 +434,11 @@ local function grant_perks(box_id, boxes)
 		end
 	end
 	if accepted >= 3 then
-		local limit = tonumber(builder:get_attribute("box_create_limit") or "3")
+		local player = minetest.get_player_by_name(builder)
+		if not player then
+			return
+		end
+		local limit = tonumber(player:get_attribute("box_create_limit") or "3")
 		if limit <= 3 then
 			minetest.log("perks: granted more boxes to " .. builder)
 			announce.all(builder .. " has been granted the more boxes perk!")
@@ -452,7 +456,7 @@ local function grant_perks(box_id, boxes)
 					"--sofar"
 				}
 			})
-			builder:set_attribute("box_create_limit", "5")
+			player:set_attribute("box_create_limit", "5")
 		end
 	end
 	if accepted >= 5 then