diff --git a/storage/itemstack.lua b/storage/itemstack.lua
index 6eb57b5..8f545ef 100644
--- a/storage/itemstack.lua
+++ b/storage/itemstack.lua
@@ -133,7 +133,8 @@ function ItemStack:getSimpleName()
     return simpleName
   end
 
-  return self:getInventory():getName().."["..self:getSlot().."]"
+  local inventory = self:getInventory()
+  return (((inventory and inventory:getName()) or inventory and "[UNKNOWN_INV]") or "[NO_INV]").."["..(self:getSlot() or "NO_SLOT").."]"
 end
 
 function ItemStack:hasChanged(listObj, thorough)