diff --git a/erpnext/buying/doctype/purchase_order/purchase_order.py b/erpnext/buying/doctype/purchase_order/purchase_order.py
index 14424dfdf4a..64c9ba36794 100644
--- a/erpnext/buying/doctype/purchase_order/purchase_order.py
+++ b/erpnext/buying/doctype/purchase_order/purchase_order.py
@@ -889,6 +889,20 @@ def make_subcontracting_order(source_name, target_doc=None, save=False, submit=F
 
 
 def get_mapped_subcontracting_order(source_name, target_doc=None):
+	def post_process(source_doc, target_doc):
+		target_doc.populate_items_table()
+
+		if target_doc.set_warehouse:
+			for item in target_doc.items:
+				item.warehouse = target_doc.set_warehouse
+		else:
+			if source_doc.set_warehouse:
+				for item in target_doc.items:
+					item.warehouse = source_doc.set_warehouse
+			else:
+				for idx, item in enumerate(target_doc.items):
+					item.warehouse = source_doc.items[idx].warehouse
+
 	if target_doc and isinstance(target_doc, str):
 		target_doc = json.loads(target_doc)
 		for key in ["service_items", "items", "supplied_items"]:
@@ -919,22 +933,9 @@ def get_mapped_subcontracting_order(source_name, target_doc=None):
 			},
 		},
 		target_doc,
+		post_process,
 	)
 
-	target_doc.populate_items_table()
-	source_doc = frappe.get_doc("Purchase Order", source_name)
-
-	if target_doc.set_warehouse:
-		for item in target_doc.items:
-			item.warehouse = target_doc.set_warehouse
-	else:
-		if source_doc.set_warehouse:
-			for item in target_doc.items:
-				item.warehouse = source_doc.set_warehouse
-		else:
-			for idx, item in enumerate(target_doc.items):
-				item.warehouse = source_doc.items[idx].warehouse
-
 	return target_doc