diff --git a/plugins/ruby/item.rb b/plugins/ruby/item.rb
index 0d65a707b..394e545c6 100644
--- a/plugins/ruby/item.rb
+++ b/plugins/ruby/item.rb
@@ -53,15 +53,26 @@ module DFHack
         end
 
         # check item flags to see if it is suitable for use as a job input material
-        def item_isfree(i)
+        def item_isfree(i, check_empty=true)
             !i.flags.trader and
             !i.flags.in_job and
-            (!i.flags.in_inventory or i.general_refs.grep(GeneralRefContainedInItemst).first) and
+            !i.flags.construction and
             !i.flags.removed and
-            !i.flags.in_building and
+            !i.flags.forbid and
+            !i.flags.dump and
             !i.flags.owned and
-            !i.flags.forbid
+            !i.flags.in_chest and   # used as hospital supply ?
+            (!i.flags.container or not check_empty or
+                !i.general_refs.find { |ir| ir.kind_of?(DFHack::GeneralRefContainsItemst) }) and
+            (!i.flags.in_inventory or
+                (!i.general_refs.find { |ir| ir.kind_of?(DFHack::GeneralRefUnitHolderst) and   # allow hauled items TODO check if holder is a thief
+                    ir.unit_tg.inventory.find { |ii| ii.item == i and ii.mode != :Hauled } } and
+                !i.general_refs.find { |ir| ir.kind_of?(DFHack::GeneralRefContainedInItemst) and
+                    !item_isfree(ir.item_tg, false) })) and
+            (!i.flags.in_building or
+                !i.general_refs.find { |ir| ir.kind_of?(DFHack::GeneralRefBuildingHolderst) and
+                    ir.building_tg.contained_items.find { |bi| bi.use_mode == 2 and bi.item == i } }) and
+            (!i.flags.on_ground or !df.map_tile_at(i).designation.hidden)      # i.flags.unk11?
         end
-        
     end
 end