diff --git a/plugins/automelt.cpp b/plugins/automelt.cpp
index 58cbdd20c..cfd348455 100644
--- a/plugins/automelt.cpp
+++ b/plugins/automelt.cpp
@@ -7,6 +7,7 @@
 #include "df/building_def.h"
 #include "df/viewscreen_dwarfmodest.h"
 #include "df/building_stockpilest.h"
+#include "modules/Buildings.h"
 #include "modules/Items.h"
 #include "df/ui.h"
 #include "modules/Maps.h"
@@ -23,10 +24,36 @@ DFHACK_PLUGIN("automelt");
 
 static const string PERSISTENCE_KEY = "automelt/stockpiles";
 
-static void mark_all_in_stockpiles(vector<PersistentStockpileInfo> &stockpiles)
+static int mark_item(df::item *item, df::item_flags bad_flags, int32_t stockpile_id)
 {
-    std::vector<df::item*> &items = world->items.other[items_other_id::IN_PLAY];
+    if (item->flags.whole & bad_flags.whole)
+        return 0;
+
+    if (item->isAssignedToThisStockpile(stockpile_id)) {
+        size_t marked_count = 0;
+        std::vector<df::item*> contents;
+        Items::getContainedItems(item, &contents);
+        for (auto child = contents.begin(); child != contents.end(); child++)
+        {
+            marked_count += mark_item(*child, bad_flags, stockpile_id);
+        }
+
+        return marked_count;
+    }
+
+    if (!can_melt(item))
+        return 0;
+
+    if (is_set_to_melt(item))
+        return 0;
+
+    insert_into_vector(world->items.other[items_other_id::ANY_MELT_DESIGNATED], &df::item::id, item);
+    item->flags.bits.melt = true;
+    return 1;
+}
 
+static void mark_all_in_stockpiles(vector<PersistentStockpileInfo> &stockpiles)
+{
     // Precompute a bitmask with the bad flags
     df::item_flags bad_flags;
     bad_flags.whole = 0;
@@ -39,27 +66,16 @@ static void mark_all_in_stockpiles(vector<PersistentStockpileInfo> &stockpiles)
 #undef F
 
     size_t marked_count = 0;
-    for (size_t i = 0; i < items.size(); i++)
+    for (auto it = stockpiles.begin(); it != stockpiles.end(); it++)
     {
-        df::item *item = items[i];
-        if (item->flags.whole & bad_flags.whole)
-            continue;
-
-        if (!can_melt(item))
-            continue;
-
-        if (is_set_to_melt(item))
+        if (!it->isValid())
             continue;
 
-        auto &melting_items = world->items.other[items_other_id::ANY_MELT_DESIGNATED];
-        for (auto it = stockpiles.begin(); it != stockpiles.end(); it++)
+        auto spid = it->getId();
+        Buildings::StockpileIterator stored;
+        for (stored.begin(it->getStockpile()); !stored.done(); ++stored)
         {
-            if (!it->inStockpile(item))
-                continue;
-
-            ++marked_count;
-            insert_into_vector(melting_items, &df::item::id, item);
-            item->flags.bits.melt = true;
+            marked_count += mark_item(*stored, bad_flags, spid);
         }
     }