diff --git a/cybersyn/scripts/central-planning.lua b/cybersyn/scripts/central-planning.lua
index 1f40126..4620bf4 100644
--- a/cybersyn/scripts/central-planning.lua
+++ b/cybersyn/scripts/central-planning.lua
@@ -102,7 +102,7 @@ local function set_comb2(map_data, station)
 		for item_name, count in pairs(deliveries) do
 			local i = #signals + 1
 			local item_type = game.item_prototypes[item_name].type
-			signals[i] = {index = i, signal = {type = item_type, name = item_name}, count = count}
+			signals[i] = {index = i, signal = {type = item_type, name = item_name}, count = -count}
 		end
 		set_combinator_output(map_data, station.entity_comb2, signals)
 	end
diff --git a/cybersyn/scripts/layout.lua b/cybersyn/scripts/layout.lua
index fbdab45..476c839 100644
--- a/cybersyn/scripts/layout.lua
+++ b/cybersyn/scripts/layout.lua
@@ -242,7 +242,8 @@ function set_r_wagon_combs(map_data, station, train)
 			local signals = {}
 
 			local inv = carriage.get_inventory(defines.inventory.cargo_wagon)
-			for stack_i, stack in ipairs(inv) do
+			for stack_i = 1, #inv do
+				local stack = inv[stack_i]
 				if stack.valid_for_read then
 					local i = #signals + 1
 					--TODO: does this work or do we need to aggregate signals?