diff --git a/src/main/java/de/jottyfan/minecraft/blockentity/ItemHoarderBlockEntity.java b/src/main/java/de/jottyfan/minecraft/blockentity/ItemHoarderBlockEntity.java
index b214fba..bb74055 100644
--- a/src/main/java/de/jottyfan/minecraft/blockentity/ItemHoarderBlockEntity.java
+++ b/src/main/java/de/jottyfan/minecraft/blockentity/ItemHoarderBlockEntity.java
@@ -127,28 +127,45 @@ public class ItemHoarderBlockEntity extends BlockEntity implements Container {
 		return stacks.isEmpty();
 	}
 
+	/**
+	 * @deprecated use getStack(String key) instead
+	 */
+	@Deprecated
 	@Override
 	public ItemStack getItem(int slot) {
 		// buggy; do not use this. The map wants to have an item name instead
 		return ItemStack.EMPTY;
 	}
 
+	/**
+	 * @deprecated use getStack(String key).setCount(0) or such instead
+	 */
+	@Deprecated
 	@Override
 	public ItemStack removeItem(int slot, int count) {
 		// buggy; do not use this. The map wants to have an item name instead
 		return ItemStack.EMPTY;
 	}
 
+	/**
+	 * @deprecated use getStack(String key).setCount(0) or such instead
+	 */
+	@Deprecated
 	@Override
 	public ItemStack removeItemNoUpdate(int slot) {
 		// buggy; do not use this. The map wants to have an item name instead
 		return ItemStack.EMPTY;
 	}
 
+	/**
+	 * @param slot is ignored; the right slot is found by itemStack's name
+	 * @param itemStack the itemStack to add
+	 */
 	@Override
 	public void setItem(int slot, ItemStack itemStack) {
-		if (slot < stacks.size()) {
-			stacks.get(itemStack.getItem().getName().getString()).grow(itemStack.getCount());
+		ItemStack found = stacks.get(itemStack.getItem().getName().getString());
+		if (found != null) {
+			found.grow(itemStack.getCount());
 		} else if (!itemStack.isEmpty()) {
 			stacks.put(itemStack.getItem().getName().getString(), itemStack);
 		}