diff --git a/erpnext/stock/doctype/packed_item/packed_item.py b/erpnext/stock/doctype/packed_item/packed_item.py
index 4f1a675..eea00ec 100644
--- a/erpnext/stock/doctype/packed_item/packed_item.py
+++ b/erpnext/stock/doctype/packed_item/packed_item.py
@@ -39,8 +39,10 @@
 	# check if exists
 	exists = 0
 	for d in doc.get("packed_items"):
-		if d.parent_item == main_item_row.item_code and d.item_code == packing_item_code and\
-				d.parent_detail_docname == main_item_row.name:
+		if d.parent_item == main_item_row.item_code and d.item_code == packing_item_code:
+			if d.parent_detail_docname != main_item_row.name:
+				d.parent_detail_docname = main_item_row.name
+
 			pi, exists = d, 1
 			break