diff --git a/loopout_test.go b/loopout_test.go
index 0e72933..a8faaf8 100644
--- a/loopout_test.go
+++ b/loopout_test.go
@@ -414,11 +414,7 @@ func TestCustomSweepConfTarget(t *testing.T) {
 // not detected our settle) and settle the off chain htlc, indicating that the
 // server successfully settled using the preimage push. In this test, we need
 // to start with a fee rate that will be too high, then progress to an
-// acceptable one. We do this by starting with a high confirmation target with
-// a high fee, and setting the default confirmation fee (which our swap will
-// drop down to if it is not confirming in time) to a lower fee. This is not
-// intuitive (lower confs having lower fees), but it allows up to mock fee
-// changes.
+// acceptable one.
 func TestPreimagePush(t *testing.T) {
 	defer test.Guard(t)()
 
@@ -426,11 +422,8 @@ func TestPreimagePush(t *testing.T) {
 	ctx := test.NewContext(t, lnd)
 	server := newServerMock(lnd)
 
-	// Start with a high confirmation delta which will have a very high fee
-	// attached to it.
 	testReq := *testRequest
-	testReq.SweepConfTarget = testLoopOutMinOnChainCltvDelta -
-		DefaultSweepConfTargetDelta - 1
+	testReq.SweepConfTarget = 10
 	testReq.Expiry = ctx.Lnd.Height + testLoopOutMinOnChainCltvDelta
 
 	// We set our mock fee estimate for our target sweep confs to be our
@@ -442,11 +435,6 @@ func TestPreimagePush(t *testing.T) {
 		),
 	)
 
-	// We set the fee estimate for our default confirmation target very
-	// low, so that once we drop down to our default confs we will start
-	// trying to sweep the preimage.
-	ctx.Lnd.SetFeeEstimate(DefaultSweepConfTarget, 1)
-
 	cfg := newSwapConfig(
 		&lnd.LndServices, newStoreMock(t), server,
 	)
@@ -520,15 +508,15 @@ func TestPreimagePush(t *testing.T) {
 	// preimage is not revealed, we also do not expect a preimage push.
 	expiryChan <- testTime
 
-	// Now, we notify the height at which the client will start using the
-	// default confirmation target. This has the effect of lowering our fees
-	// so that the client still start sweeping.
-	defaultConfTargetHeight := ctx.Lnd.Height + testLoopOutMinOnChainCltvDelta -
-		DefaultSweepConfTargetDelta
-	blockEpochChan <- defaultConfTargetHeight
+	// Now we decrease our fees for the swap's confirmation target to less
+	// than the maximum miner fee.
+	ctx.Lnd.SetFeeEstimate(testReq.SweepConfTarget, chainfee.SatPerKWeight(
+		testReq.MaxMinerFee/2,
+	))
 
-	// This time when we tick the expiry chan, our fees are lower than the
-	// swap max, so we expect it to prompt a sweep.
+	// Now when we report a new block and tick our expiry fee timer, and
+	// fees are acceptably low so we expect our sweep to be published.
+	blockEpochChan <- ctx.Lnd.Height + 2
 	expiryChan <- testTime
 
 	// Expect a signing request for the HTLC success transaction.
diff --git a/test/lnd_services_mock.go b/test/lnd_services_mock.go
index 7e162a2..7d3466c 100644
--- a/test/lnd_services_mock.go
+++ b/test/lnd_services_mock.go
@@ -258,5 +258,5 @@ func (s *LndMockServices) DecodeInvoice(request string) (*zpay32.Invoice,
 func (s *LndMockServices) SetFeeEstimate(confTarget int32,
 	feeEstimate chainfee.SatPerKWeight) {
 
-	s.WalletKit.(*mockWalletKit).feeEstimates[confTarget] = feeEstimate
+	s.WalletKit.(*mockWalletKit).setFeeEstimate(confTarget, feeEstimate)
 }
diff --git a/test/walletkit_mock.go b/test/walletkit_mock.go
index b961162..19738a8 100644
--- a/test/walletkit_mock.go
+++ b/test/walletkit_mock.go
@@ -3,6 +3,7 @@ package test
 import (
 	"context"
 	"errors"
+	"sync"
 	"time"
 
 	"github.com/btcsuite/btcd/chaincfg"
@@ -21,9 +22,11 @@ import (
 var DefaultMockFee = chainfee.SatPerKWeight(10000)
 
 type mockWalletKit struct {
-	lnd          *LndMockServices
-	keyIndex     int32
-	feeEstimates map[int32]chainfee.SatPerKWeight
+	lnd      *LndMockServices
+	keyIndex int32
+
+	feeEstimateLock sync.Mutex
+	feeEstimates    map[int32]chainfee.SatPerKWeight
 }
 
 var _ lndclient.WalletKitClient = (*mockWalletKit)(nil)
@@ -118,9 +121,19 @@ func (m *mockWalletKit) SendOutputs(ctx context.Context, outputs []*wire.TxOut,
 	return &tx, nil
 }
 
+func (m *mockWalletKit) setFeeEstimate(confTarget int32, fee chainfee.SatPerKWeight) {
+	m.feeEstimateLock.Lock()
+	defer m.feeEstimateLock.Unlock()
+
+	m.feeEstimates[confTarget] = fee
+}
+
 func (m *mockWalletKit) EstimateFee(ctx context.Context, confTarget int32) (
 	chainfee.SatPerKWeight, error) {
 
+	m.feeEstimateLock.Lock()
+	defer m.feeEstimateLock.Unlock()
+
 	if confTarget <= 1 {
 		return 0, errors.New("conf target must be greater than 1")
 	}