diff --git a/lignumis/prototypes/content/steam-assembling-machine.lua b/lignumis/prototypes/content/steam-assembling-machine.lua
index 2a6871e..ed85a59 100644
--- a/lignumis/prototypes/content/steam-assembling-machine.lua
+++ b/lignumis/prototypes/content/steam-assembling-machine.lua
@@ -76,7 +76,8 @@ data:extend({
         pick_sound = item_sounds.mechanical_inventory_pickup,
         drop_sound = item_sounds.mechanical_inventory_move,
         place_result = "steam-assembling-machine",
-        stack_size = 50
+        stack_size = 50,
+        weight = 20 * kg
     },
     {
         type = "recipe",
diff --git a/lignumis/prototypes/integrations/vanilla.lua b/lignumis/prototypes/integrations/vanilla.lua
index 9b33ad5..16b0477 100644
--- a/lignumis/prototypes/integrations/vanilla.lua
+++ b/lignumis/prototypes/integrations/vanilla.lua
@@ -334,4 +334,16 @@ if settings.startup["lignumis-fulgora-wood"].value then
     if recycler.result_inventory_size < recycling_result_count then
         recycler.result_inventory_size = recycling_result_count
     end
-end
\ No newline at end of file
+end
+
+
+-- Fix item weights
+
+local function set_default_weight(item, items_per_rocket)
+    data.raw.item[item].weight = data.raw.item[item].weight or 1000 * kg / items_per_rocket
+end
+set_default_weight("electronic-circuit", 2000)
+set_default_weight("advanced-circuit", 1000)
+set_default_weight("processing-unit", 300)
+set_default_weight("low-density-structure", 200)
+set_default_weight("rocket-fuel", 100)
\ No newline at end of file