diff --git a/test/functional/test_framework/wallet.py b/test/functional/test_framework/wallet.py
index 14c047f71..009d50e07 100644
--- a/test/functional/test_framework/wallet.py
+++ b/test/functional/test_framework/wallet.py
@@ -1,64 +1,65 @@
 #!/usr/bin/env python3
 # Copyright (c) 2020 The Bitcoin Core developers
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 """A limited-functionality wallet, which may replace a real wallet in tests"""
 
 from decimal import Decimal
 
 from test_framework.address import (
     ADDRESS_ECREG_P2SH_OP_TRUE,
     SCRIPTSIG_OP_TRUE,
 )
 from test_framework.messages import XEC, COutPoint, CTransaction, CTxIn, CTxOut
 from test_framework.txtools import pad_tx
 from test_framework.util import assert_equal, hex_str_to_bytes, satoshi_round
 
 
 class MiniWallet:
     def __init__(self, test_node):
         self._test_node = test_node
         self._utxos = []
         self._address = ADDRESS_ECREG_P2SH_OP_TRUE
         self._scriptPubKey = hex_str_to_bytes(
             self._test_node.validateaddress(
                 self._address)['scriptPubKey'])
 
     def generate(self, num_blocks):
         """Generate blocks with coinbase outputs to the internal address,
         and append the outputs to the internal list"""
         blocks = self._test_node.generatetoaddress(num_blocks, self._address)
         for b in blocks:
             cb_tx = self._test_node.getblock(blockhash=b, verbosity=2)['tx'][0]
             self._utxos.append(
                 {'txid': cb_tx['txid'], 'vout': 0, 'value': cb_tx['vout'][0]['value']})
         return blocks
 
-    def send_self_transfer(self, *, fee_rate, from_node):
+    def send_self_transfer(self, *, fee_rate=Decimal("3000.00"), from_node,
+                           utxo_to_spend=None):
         """Create and send a tx with the specified fee_rate. Fee may be exact
          or at most one satoshi higher than needed."""
         self._utxos = sorted(self._utxos, key=lambda k: k['value'])
-        # Pick the largest utxo and hope it covers the fee
-        largest_utxo = self._utxos.pop()
+        # Pick the largest utxo (if none provided) and hope it covers the fee
+        utxo_to_spend = utxo_to_spend or self._utxos.pop()
 
         # The size will be enforced by pad_tx()
         size = 100
         send_value = satoshi_round(
-            largest_utxo['value'] - fee_rate * (Decimal(size) / 1000))
-        fee = largest_utxo['value'] - send_value
+            utxo_to_spend['value'] - fee_rate * (Decimal(size) / 1000))
+        fee = utxo_to_spend['value'] - send_value
         assert send_value > 0
 
         tx = CTransaction()
-        tx.vin = [CTxIn(COutPoint(int(largest_utxo['txid'], 16),
-                                  largest_utxo['vout']))]
+        tx.vin = [CTxIn(COutPoint(int(utxo_to_spend['txid'], 16),
+                                  utxo_to_spend['vout']))]
         tx.vout = [CTxOut(int(send_value * XEC), self._scriptPubKey)]
         tx.vin[0].scriptSig = SCRIPTSIG_OP_TRUE
         pad_tx(tx, size)
         tx_hex = tx.serialize().hex()
 
         txid = from_node.sendrawtransaction(tx_hex)
         self._utxos.append({'txid': txid, 'vout': 0, 'value': send_value})
         tx_info = from_node.getmempoolentry(txid)
         assert_equal(tx_info['size'], size)
         assert_equal(tx_info['fee'], fee)
         return {'txid': txid, 'hex': tx_hex}