diff --git a/src/main/java/gregtech/api/capability/impl/ItemHandlerList.java b/src/main/java/gregtech/api/capability/impl/ItemHandlerList.java
index 08f8a70957b..ffb12d0dcd6 100644
--- a/src/main/java/gregtech/api/capability/impl/ItemHandlerList.java
+++ b/src/main/java/gregtech/api/capability/impl/ItemHandlerList.java
@@ -48,11 +48,12 @@ public int getSlots() {
     public void setStackInSlot(int slot, @NotNull ItemStack stack) {
         if (invalidSlot(slot)) return;
         IItemHandler itemHandler = handlerBySlotIndex.get(slot);
+        int actualSlot = slot - baseIndexOffset.get(itemHandler);
         if (itemHandler instanceof IItemHandlerModifiable modifiable) {
-            modifiable.setStackInSlot(slot - baseIndexOffset.get(itemHandler), stack);
+            modifiable.setStackInSlot(actualSlot, stack);
         } else {
-            itemHandler.extractItem(slot, Integer.MAX_VALUE, false);
-            itemHandler.insertItem(slot, stack, false);
+            itemHandler.extractItem(actualSlot, Integer.MAX_VALUE, false);
+            itemHandler.insertItem(actualSlot, stack, false);
         }
     }