diff --git a/libs/cache.lua b/libs/cache.lua
index cde47cb..3d18680 100644
--- a/libs/cache.lua
+++ b/libs/cache.lua
@@ -8,26 +8,7 @@ cache.citems = {}
 -----------------------------------------------------
 -- Add an Item to the cache
 -----------------------------------------------------
-function cache.add_item(def)
-
-	-- special handling for doors. In inventory the item should be displayed instead of the node_a/node_b
-	local item_def
-
-	if def.groups and def.groups.door then
-		if def.door then
-			item_def = minetest.registered_items[def.door.name]
-		elseif def.drop and type(def.drop) == "string" then
-			item_def = minetest.registered_items[def.drop]
-		else
-			item_def = def
-		end
-		if not item_def then
-			minetest.log("[smart_inventory] Buggy door found: "..def.name)
-			item_def = def
-		end
-	else
-		item_def = def
-	end
+function cache.add_item(item_def)
 
 	-- already in cache. Skip duplicate processing
 	if cache.citems[item_def.name] then
@@ -49,7 +30,7 @@ function cache.add_item(def)
 	cache.citems[item_def.name] = entry
 	-- classify the item
 	for _, flt in pairs(filter.registered_filter) do
-		local filter_result = flt:check_item_by_def(def)
+		local filter_result = flt:check_item_by_def(item_def)
 		if filter_result then
 			if filter_result == true then
 				cache.assign_to_group(flt.name, item_def, flt)
diff --git a/libs/filter.lua b/libs/filter.lua
index 27a0c86..611538c 100644
--- a/libs/filter.lua
+++ b/libs/filter.lua
@@ -216,8 +216,17 @@ end
 filter.register_filter({
 		name = "shape",
 		check_item_by_def = function(self, def)
+			local door_groups
+			if shaped_groups["door"] then
+				local door_filter = filter.get("door")
+				door_groups = door_filter:check_item_by_def(def)
+				if door_groups and door_groups.door then
+					return true
+				end
+			end
+
 			for k, v in pairs(def.groups) do
-				if shaped_groups[k] then
+				if k ~= "door" and shaped_groups[k] then
 					return true
 				end
 			end
@@ -356,6 +365,45 @@ filter.register_filter({
 		end
 	})
 
+
+local door_groups
+local function fill_door_groups()
+	door_groups = {}
+	for _, extend_def in pairs(minetest.registered_items) do
+		local base_def
+		if extend_def.groups and extend_def.groups.door then
+			if extend_def.door then
+				base_def = minetest.registered_items[extend_def.door.name]
+			elseif extend_def.drop and type(extend_def.drop) == "string" then
+				base_def = minetest.registered_items[extend_def.drop]
+			end
+		end
+		if base_def then
+			door_groups[base_def.name] = extend_def
+			door_groups[extend_def.name] = false
+		end
+	end
+end
+
+filter.register_filter({
+		name = "door",
+		check_item_by_def = function(self, def)
+			if not door_groups then
+				fill_door_groups()
+			end
+			if not door_groups[def.name] then
+				return
+			end
+
+			local group_filter = filter.get("group")
+			local ret = group_filter:check_item_by_def(door_groups[def.name])
+			if ret then
+				ret["not_in_creative_inventory"] = nil
+				return ret
+			end
+		end
+	})
+
 ----------------
 return filter