diff --git a/erpnext/controllers/sales_and_purchase_return.py b/erpnext/controllers/sales_and_purchase_return.py
index 7b03705..7979226 100644
--- a/erpnext/controllers/sales_and_purchase_return.py
+++ b/erpnext/controllers/sales_and_purchase_return.py
@@ -204,6 +204,8 @@
 	return items
 
 def get_returned_qty_map_for_row(row_name, doctype):
+	if doctype == "POS Invoice": return {}
+
 	child_doctype = doctype + " Item"
 	reference_field = "dn_detail" if doctype == "Delivery Note" else frappe.scrub(child_doctype)