diff --git a/TwosideKeeper.jar b/TwosideKeeper.jar
index 1bfde2e..5566518 100644
Binary files a/TwosideKeeper.jar and b/TwosideKeeper.jar differ
diff --git a/src/sig/plugin/TwosideKeeper/HelperStructures/Utils/InventoryUtils.java b/src/sig/plugin/TwosideKeeper/HelperStructures/Utils/InventoryUtils.java
index 7babe0b..ca49e88 100644
--- a/src/sig/plugin/TwosideKeeper/HelperStructures/Utils/InventoryUtils.java
+++ b/src/sig/plugin/TwosideKeeper/HelperStructures/Utils/InventoryUtils.java
@@ -84,4 +84,12 @@ public class InventoryUtils {
 		}
 		return remaining;
 	}
+	public static boolean InventoryContainSameMaterial(Inventory inv, ItemStack item) {
+		for (ItemStack i : inv.getContents()) {
+			if (i!=null && item!=null && i.getType()==item.getType()) {
+				return true;
+			}
+		}
+		return false;
+	}
 }
diff --git a/src/sig/plugin/TwosideKeeper/HelperStructures/Utils/ItemCubeUtils.java b/src/sig/plugin/TwosideKeeper/HelperStructures/Utils/ItemCubeUtils.java
index f2f25b7..34ab325 100644
--- a/src/sig/plugin/TwosideKeeper/HelperStructures/Utils/ItemCubeUtils.java
+++ b/src/sig/plugin/TwosideKeeper/HelperStructures/Utils/ItemCubeUtils.java
@@ -46,7 +46,7 @@ public class ItemCubeUtils {
 		HashMap<Integer,ItemStack> reject_items = new HashMap<Integer,ItemStack>();
 		for (ItemStack it : remaining) {
 			if (it!=null) {
-				if (inv.containsAtLeast(it, 1)) {
+				if (InventoryUtils.InventoryContainSameMaterial(inv, it)) {
 					HashMap<Integer,ItemStack> extras = cube_inv.addItem(it);
 					if (extras.size()==0) {
 						List<ItemStack> itemslist = new ArrayList<ItemStack>();