diff --git a/erpnext/accounts/doctype/pos_invoice_merge_log/pos_invoice_merge_log.py b/erpnext/accounts/doctype/pos_invoice_merge_log/pos_invoice_merge_log.py
index a183a5ee6aa..8c8fa09a292 100644
--- a/erpnext/accounts/doctype/pos_invoice_merge_log/pos_invoice_merge_log.py
+++ b/erpnext/accounts/doctype/pos_invoice_merge_log/pos_invoice_merge_log.py
@@ -389,7 +389,9 @@ def split_invoices(invoices):
 			if not item.serial_no:
 				continue
 
-			return_against_is_added = any(d for d in _invoices if d.pos_invoice == pos_invoice.return_against)
+			return_against_is_added = any(
+				d for d in _invoices if d[0].pos_invoice == pos_invoice.return_against
+			)
 			if return_against_is_added:
 				break