diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
new file mode 100644
index 0000000..980d40a
--- /dev/null
+++ b/.github/workflows/build.yml
@@ -0,0 +1,11 @@
+on: [push, pull_request]
+name: build
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@master
+      - name: lint
+        uses: Roang-zero1/factorio-mod-luacheck@master
+        with:
+          luacheckrc_url: https://raw.githubusercontent.com/minetest-mods/item_drop/master/.luacheckrc
diff --git a/.luacheckrc b/.luacheckrc
new file mode 100644
index 0000000..a9c034e
--- /dev/null
+++ b/.luacheckrc
@@ -0,0 +1,19 @@
+unused_args = false
+allow_defined_top = true
+max_line_length = 999
+
+ignore = {
+    "name", "drops", "i",
+}
+
+globals = {
+    "minetest",
+}
+
+read_globals = {
+    string = {fields = {"split", "trim"}},
+    table = {fields = {"copy", "getn"}},
+
+    "vector", "ItemStack",
+    "dump",
+}
diff --git a/README.md b/README.md
index 3fa0895..771e82d 100644
--- a/README.md
+++ b/README.md
@@ -1,15 +1,14 @@
-# item_drop
+# Item Drop [![](https://github.com/minetest-mods/item_drop/workflows/build/badge.svg)](https://github.com/minetest-mods/item_drop/actions) [![License](https://img.shields.io/badge/license-LGPLv2.1%2B-blue.svg)](https://www.gnu.org/licenses/old-licenses/lgpl-2.1.en.html)
+
+A highly configurable mod providing item magnet and in-world node drops\
 By [PilzAdam](https://github.com/PilzAdam),
 [texmex](https://github.com/tacotexmex/), [hybriddog](https://github.com/hybriddog/).
 
-## Description
-A highly configurable mod providing item magnet and in-world node drops
-
 ## Licensing
 LGPLv2.1/CC BY-SA 3.0. Particle code from WCILA mod by Aurailus, originally licensed MIT.
 
 ## Notes
-item_drop can be played with Minetest 0.4.16 or above. It was originally
+`item_drop` can be played with Minetest 0.4.16 or above. It was originally
 developed by [PilzAdam](https://github.com/PilzAdam/item_drop).
 
 ## List of features
diff --git a/init.lua b/init.lua
index 7f90680..57efdbf 100644
--- a/init.lua
+++ b/init.lua
@@ -103,7 +103,7 @@ if legacy_setting_getbool("item_drop.enable_item_pickup",
 		if pickup_particle then
 			local item = minetest.registered_nodes[
 				ent.itemstring:gsub("(.*)%s.*$", "%1")]
-			local image = ""
+			local image
 			if item and item.tiles and item.tiles[1] then
 				if inventorycube_drawtypes[item.drawtype] then
 					local tiles = item.tiles
@@ -201,9 +201,9 @@ if legacy_setting_getbool("item_drop.enable_item_pickup",
 			local itemdef = minetest.registered_entities["__builtin:item"]
 			local old_on_step = itemdef.on_step
 			local function do_nothing() end
-			function itemdef.on_step(self, dtime)
+			function itemdef.on_step(self, ...)
 				if not self.is_magnet_item then
-					return old_on_step(self, dtime)
+					return old_on_step(self, ...)
 				end
 				ObjectRef = ObjectRef or getmetatable(self.object)
 				local old_funcs = {}
@@ -212,7 +212,7 @@ if legacy_setting_getbool("item_drop.enable_item_pickup",
 					old_funcs[method] = ObjectRef[method]
 					ObjectRef[method] = do_nothing
 				end
-				old_on_step(self, dtime)
+				old_on_step(self, ...)
 				for i = 1, #blocked_methods do
 					local method = blocked_methods[i]
 					ObjectRef[method] = old_funcs[method]
@@ -252,6 +252,13 @@ if legacy_setting_getbool("item_drop.enable_item_pickup",
 		return keys_pressed ~= key_invert
 	end
 
+	local function is_inside_map(pos)
+		local bound = 31000
+		return -bound < pos.x and pos.x < bound
+			and -bound < pos.y and pos.y < bound
+			and -bound < pos.z and pos.z < bound
+	end
+
 	-- called for each player to possibly collect an item, returns true if so
 	local function pickupfunc(player)
 		if not has_keys_pressed(player)
@@ -261,8 +268,12 @@ if legacy_setting_getbool("item_drop.enable_item_pickup",
 		end
 
 		local pos = player:get_pos()
+		if not is_inside_map(pos) then
+			-- get_objects_inside_radius crashes for too far positions
+			return
+		end
 		pos.y = pos.y+0.5
-		local inv
+		local inv = player:get_inventory()
 
 		local objectlist = minetest.get_objects_inside_radius(pos,
 			magnet_mode and magnet_radius or pickup_radius)
@@ -271,14 +282,6 @@ if legacy_setting_getbool("item_drop.enable_item_pickup",
 			local ent = opt_get_ent(object)
 			if ent
 			and item_drop.can_pickup(ent, player) then
-				if not inv then
-					inv = player:get_inventory()
-					if not inv then
-						minetest.log("error", "[item_drop] Couldn't " ..
-							"get inventory")
-						return
-					end
-				end
 				local item = ItemStack(ent.itemstring)
 				if inv:room_for_item("main", item) then
 					local flying_item
@@ -409,8 +412,24 @@ and not minetest.settings:get_bool("creative_mode") then
 			end
 		end
 	end
-end
 
+	local function pickup_step()
+		local got_item
+		local players = minetest.get_connected_players()
+		for i = 1,#players do
+			got_item = got_item or pickupfunc(players[i])
+		end
+		-- lower step if takeable item(s) were found
+		local time
+		if got_item then
+			time = 0.02
+		else
+			time = 0.2
+		end
+		minetest.after(time, pickup_step)
+	end
+	minetest.after(3.0, pickup_step)
+end
 
 local time = (minetest.get_us_time() - load_time_start) / 1000000
 local msg = "[item_drop] loaded after ca. " .. time .. " seconds."