diff --git a/lib/paymentrequest.py b/lib/paymentrequest.py
index b57714441..51fbcbe97 100644
--- a/lib/paymentrequest.py
+++ b/lib/paymentrequest.py
@@ -273,7 +273,7 @@ class PaymentRequest:
         paymnt.merchant_data = pay_det.merchant_data
         paymnt.transactions.append(bfh(raw_tx))
         ref_out = paymnt.refund_to.add()
-        ref_out.script = transaction.Transaction.pay_script(TYPE_ADDRESS, refund_addr)
+        ref_out.script = util.bfh(transaction.Transaction.pay_script(TYPE_ADDRESS, refund_addr))
         paymnt.memo = "Paid using Electrum"
         pm = paymnt.SerializeToString()
         payurl = urllib.parse.urlparse(pay_det.payment_url)