diff --git a/README.txt b/README.txt
index 8566052..76745d6 100644
--- a/README.txt
+++ b/README.txt
@@ -1,6 +1,6 @@
 Minetest mod "Inventory Tweaks"
 ===============================
-version: 2.0
+version: 2.0.1
 
 License of source code: WTFPL
 -----------------------------
diff --git a/init.lua b/init.lua
index 0a5583a..b022be1 100644
--- a/init.lua
+++ b/init.lua
@@ -34,6 +34,9 @@ local function add_buttons(player, formspec)
 		formspec = player:get_inventory_formspec()
 	end
 	local w,h = get_formspec_size(formspec)
+	if not w or not h then
+		return
+	end
 	for i=1,#tweak.buttons do
 		formspec = formspec .. "button["..w-2+(i*0.5)..",-0.2;" .. tweak.buttons[i]
 	end