diff --git a/erpnext/accounts/doctype/payment_request/payment_request.py b/erpnext/accounts/doctype/payment_request/payment_request.py
index 0c46191..f2679ba 100644
--- a/erpnext/accounts/doctype/payment_request/payment_request.py
+++ b/erpnext/accounts/doctype/payment_request/payment_request.py
@@ -211,7 +211,10 @@
 		grand_total = flt(ref_doc.grand_total) - flt(ref_doc.advance_paid)
 		
 	if dt == "Sales Invoice":
-		grand_total = flt(ref_doc.grand_total)
+		if ref_doc.party_account_currency == ref_doc.currency:
+			grand_total = flt(ref_doc.outstanding_amount)
+		else:
+			grand_total = flt(ref_doc.outstanding_amount) / ref_doc.conversion_rate
 		
 	if grand_total > 0 :
 		return grand_total