diff --git a/common/buildcraft/factory/TileHopper.java b/common/buildcraft/factory/TileHopper.java
index 3b8a37bd..56ef8bda 100644
--- a/common/buildcraft/factory/TileHopper.java
+++ b/common/buildcraft/factory/TileHopper.java
@@ -50,7 +50,7 @@ public class TileHopper extends TileBuildCraft implements IInventory {
 			if(stackInSlot == null) continue;
 
 			ItemStack clonedStack = stackInSlot.copy().splitStack(1);
-			if (transactor.addItem(clonedStack, ForgeDirection.UP, true).stackSize <= 0) {
+			if (transactor.add(clonedStack, ForgeDirection.UP, true).stackSize > 0) {
 				_inventory.decrStackSize(internalSlot, 1);
 				return;
 			}