diff --git a/microwave_oven.lua b/microwave_oven.lua
index 512ad1b7..fa0ad527 100644
--- a/microwave_oven.lua
+++ b/microwave_oven.lua
@@ -285,7 +285,7 @@ minetest.register_abm({
 			return
 		end
 
-		if inv:room_for_item("dst",cooked.item) then
+		if not inv:room_for_item("dst",cooked.item) then
 			meta:set_string("infotext", S("Oven output bins are full"))
 			hacky_swap_node(pos, "homedecor:microwave_oven")
 			meta:set_string("formspec", mw_oven_inactive_formspec)