diff --git a/src/main/java/org/ultramine/server/tools/ItemBlocker.java b/src/main/java/org/ultramine/server/tools/ItemBlocker.java
index 4877d1d..913312b 100644
--- a/src/main/java/org/ultramine/server/tools/ItemBlocker.java
+++ b/src/main/java/org/ultramine/server/tools/ItemBlocker.java
@@ -124,6 +124,8 @@
 						if(slot.inventory == null || slot.getSlotIndex() >= slot.inventory.getSizeInventory())
 							continue; //Fix for some broken containers
 						ItemStack is = slot.getStack();
+						if(is == null)
+							continue;
 						if(is.getItem() == null)
 						{//Fix for broken items
 							slot.putStack(null);