diff --git a/erpnext/stock/doctype/serial_and_batch_bundle/serial_and_batch_bundle.py b/erpnext/stock/doctype/serial_and_batch_bundle/serial_and_batch_bundle.py
index 8d216171641..d9071c406a2 100644
--- a/erpnext/stock/doctype/serial_and_batch_bundle/serial_and_batch_bundle.py
+++ b/erpnext/stock/doctype/serial_and_batch_bundle/serial_and_batch_bundle.py
@@ -1390,13 +1390,15 @@ class SerialandBatchBundle(Document):
 
 		so_name, so_detail_no = frappe.db.get_value(
 			"Delivery Note Item", self.voucher_detail_no, ["against_sales_order", "so_detail"]
-		)
+		) or [None, None]
 
 		if so_name and so_detail_no:
 			sre_names = get_sre_against_so_for_dn(so_name, so_detail_no)
 
 			return sre_names
 
+		return None
+
 
 @frappe.whitelist()
 def download_blank_csv_template(content):