diff --git a/CHANGELOG.md b/CHANGELOG.md
index aa92e67..9317d24 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,17 @@ and this project adheres to the versioning of Factorio, so 0.18.x will be at lea
 
 ## [Released]
 
+## [0.18.4] - 2020-06-07
+### General
+Based onyuser feedback updated the mod
+
+### Changed
+- Window now remember last location when opened
+
+### Fixed
+- On multiplayer session the window would lag behind while dragging, because the location would be saved on server. This isn't going to happen anymore, hopefully (not tested yet).
+- When window is moved out of boundaries, when reopened, it will correct itself to be fully in sight again.
+
 ## [0.18.3] - 2020-06-07
 ### General
 A small visual overhaul of the mod
diff --git a/calculator.lua b/calculator.lua
index 1940ac1..aa5f15f 100644
--- a/calculator.lua
+++ b/calculator.lua
@@ -40,6 +40,28 @@ local function destroy_calculator(player)
 end
 
 -- ----------------------------------------------------------------
+function fix_oob_ui(player)
+	if global.gui_position[player.index].x < 0 then
+		global.gui_position[player.index].x = 0
+	end
+	if global.gui_position[player.index].y < 0 then
+		global.gui_position[player.index].y = 0
+	end
+
+	-- TODO fixed box size, because there is no API call for that
+	local width = 255
+	local height = 350
+
+	if global.gui_position[player.index].x + width > player.display_resolution.width then
+		global.gui_position[player.index].x = player.display_resolution.width - width
+	end
+	if global.gui_position[player.index].y + height > player.display_resolution.height then
+		global.gui_position[player.index].y = player.display_resolution.height - height
+	end
+	--global.gui_position[player.index]
+end
+
+-- ----------------------------------------------------------------
 function show_calculator(player)
 	local root = get_gui_root(player)
 
@@ -130,8 +152,6 @@ function show_calculator(player)
 		row5.add({type="sprite-button", style="calcui_button_style_dark",  caption=".",  name="calcui_button_DOT"}).sprite = "sprite_calcui_dark"
 		row5.add({type="sprite-button", style="calcui_button_style_red",   caption="=",  name="calcui_button_EQU"}).sprite = "sprite_calcui_red"
 
-		--.sprite = "sprite_calcui_dark"
-
 		local col2 = table.add({
 			type = "flow", 
 			name = "calcui_table_col2", 
@@ -170,8 +190,18 @@ function show_calculator(player)
 		recents.style.column_alignments[1] = "right"
 		
 		
-		-- center the gui
-		calcui.force_auto_center()
+		-- use last saved location or center the gui
+		if not global.gui_position then
+			global.gui_position = {}
+		end
+		if global.gui_position[player.index] then
+			-- fix weird saved positions (out of reach)
+			fix_oob_ui(player)
+			
+			calcui.location = global.gui_position[player.index]
+		else
+			calcui.force_auto_center()
+		end
 	end
 end
 
@@ -447,8 +477,10 @@ end
 -- ----------------------------------------------------------------
 function calcui_on_gui_location_changed(event)
 	if event.element.name == "calcui" then
-		local player = game.players[event.player_index]
-		local root = get_gui_root(player)
-		root.calcui.location = event.element.location
+		local root = get_gui_root(game.players[event.player_index])
+		if not global.gui_position then
+			global.gui_position = {}
+		end
+		global.gui_position[event.player_index] = event.element.location
 	end
 end
\ No newline at end of file
diff --git a/info.json b/info.json
index 1672cd0..ed26d3f 100644
--- a/info.json
+++ b/info.json
@@ -1,6 +1,6 @@
 {
 	"name": "calculator-ui",
-	"version": "0.18.3",
+	"version": "0.18.4",
 	"title": "Calculator UI",
 	"author": "Wichu",
 	"factorio_version": "0.18",