diff --git a/src/main/java/net/minecraftforge/items/SlotItemHandler.java b/src/main/java/net/minecraftforge/items/SlotItemHandler.java
index 81b7f03c4..25d0889c4 100644
--- a/src/main/java/net/minecraftforge/items/SlotItemHandler.java
+++ b/src/main/java/net/minecraftforge/items/SlotItemHandler.java
@@ -43,10 +43,27 @@ public class SlotItemHandler extends Slot
     @Override
     public boolean isItemValid(@Nonnull ItemStack stack)
     {
-        if (stack.isEmpty())
+        if (stack.isEmpty() || !itemHandler.isItemValid(index, stack))
             return false;
 
-        return itemHandler.isItemValid(index, stack);
+        IItemHandler handler = this.getItemHandler();
+        ItemStack remainder;
+        if (handler instanceof IItemHandlerModifiable)
+        {
+            IItemHandlerModifiable handlerModifiable = (IItemHandlerModifiable) handler;
+            ItemStack currentStack = handlerModifiable.getStackInSlot(index);
+
+            handlerModifiable.setStackInSlot(index, ItemStack.EMPTY);
+
+            remainder = handlerModifiable.insertItem(index, stack, true);
+
+            handlerModifiable.setStackInSlot(index, currentStack);
+        }
+        else
+        {
+            remainder = handler.insertItem(index, stack, true);
+        }
+        return remainder.getCount() < stack.getCount();
     }
 
     @Override