diff --git a/test/functional/wallet.py b/test/functional/wallet.py
--- a/test/functional/wallet.py
+++ b/test/functional/wallet.py
@@ -5,6 +5,7 @@
 """Test the wallet."""
 from test_framework.test_framework import BitcoinTestFramework
 from test_framework.util import *
+from test_framework.mininode import *
 
 
 class WalletTest(BitcoinTestFramework):
@@ -153,14 +154,16 @@
         assert_equal(self.nodes[2].getbalance("from1"), 94 - 21)
 
         # Send 10 BTC normal
+        old_balance = self.nodes[2].getbalance()
         address = self.nodes[0].getnewaddress("test")
         fee_per_byte = Decimal('0.001') / 1000
         self.nodes[2].settxfee(fee_per_byte * 1000)
         txid = self.nodes[2].sendtoaddress(address, 10, "", "", False)
         self.nodes[2].generate(1)
         self.sync_all([self.nodes[0:3]])
-        node_2_bal = self.check_fee_amount(self.nodes[2].getbalance(), Decimal(
-            '84'), fee_per_byte, count_bytes(self.nodes[2].getrawtransaction(txid)))
+        ctx = FromHex(CTransaction(), self.nodes[2].getrawtransaction(txid))
+        node_2_bal = self.check_fee_amount(self.nodes[2].getbalance(), old_balance - Decimal('10'),
+                                           fee_per_byte, ctx.billable_size())
         assert_equal(self.nodes[0].getbalance(), Decimal('10'))
 
         # Send 10 BTC with subtract fee from amount
@@ -177,8 +180,9 @@
         self.nodes[2].generate(1)
         self.sync_all([self.nodes[0:3]])
         node_0_bal += Decimal('10')
+        ctx = FromHex(CTransaction(), self.nodes[2].getrawtransaction(txid))
         node_2_bal = self.check_fee_amount(self.nodes[2].getbalance(
-        ), node_2_bal - Decimal('10'), fee_per_byte, count_bytes(self.nodes[2].getrawtransaction(txid)))
+        ), node_2_bal - Decimal('10'), fee_per_byte, ctx.billable_size())
         assert_equal(self.nodes[0].getbalance(), node_0_bal)
 
         # Sendmany 10 BTC with subtract fee from amount
@@ -187,8 +191,9 @@
         self.sync_all([self.nodes[0:3]])
         node_2_bal -= Decimal('10')
         assert_equal(self.nodes[2].getbalance(), node_2_bal)
+        ctx = FromHex(CTransaction(), self.nodes[2].getrawtransaction(txid))
         node_0_bal = self.check_fee_amount(self.nodes[0].getbalance(
-        ), node_0_bal + Decimal('10'), fee_per_byte, count_bytes(self.nodes[2].getrawtransaction(txid)))
+        ), node_0_bal + Decimal('10'), fee_per_byte, ctx.billable_size())
 
         # Test ResendWalletTransactions:
         # Create a couple of transactions, then start up a fourth