diff --git a/device/device_test.go b/device/device_test.go
index 01ee2ac..1716f92 100644
--- a/device/device_test.go
+++ b/device/device_test.go
@@ -314,30 +314,6 @@ func TestConcurrencySafety(t *testing.T) {
 	close(done)
 }
 
-func assertNil(t *testing.T, err error) {
-	if err != nil {
-		t.Fatal(err)
-	}
-}
-
-func assertEqual(t *testing.T, a, b []byte) {
-	if !bytes.Equal(a, b) {
-		t.Fatal(a, "!=", b)
-	}
-}
-
-func randDevice(t *testing.T) *Device {
-	sk, err := newPrivateKey()
-	if err != nil {
-		t.Fatal(err)
-	}
-	tun := newDummyTUN("dummy")
-	logger := NewLogger(LogLevelError, "")
-	device := NewDevice(tun, conn.NewDefaultBind(), logger)
-	device.SetPrivateKey(sk)
-	return device
-}
-
 func BenchmarkLatency(b *testing.B) {
 	pair := genTestPair(b)
 
diff --git a/device/noise_test.go b/device/noise_test.go
index dbf2c7d..807ca2d 100644
--- a/device/noise_test.go
+++ b/device/noise_test.go
@@ -9,6 +9,9 @@ import (
 	"bytes"
 	"encoding/binary"
 	"testing"
+
+	"golang.zx2c4.com/wireguard/conn"
+	"golang.zx2c4.com/wireguard/tun/tuntest"
 )
 
 func TestCurveWrappers(t *testing.T) {
@@ -29,6 +32,30 @@ func TestCurveWrappers(t *testing.T) {
 	}
 }
 
+func randDevice(t *testing.T) *Device {
+	sk, err := newPrivateKey()
+	if err != nil {
+		t.Fatal(err)
+	}
+	tun := tuntest.NewChannelTUN()
+	logger := NewLogger(LogLevelError, "")
+	device := NewDevice(tun.TUN(), conn.NewDefaultBind(), logger)
+	device.SetPrivateKey(sk)
+	return device
+}
+
+func assertNil(t *testing.T, err error) {
+	if err != nil {
+		t.Fatal(err)
+	}
+}
+
+func assertEqual(t *testing.T, a, b []byte) {
+	if !bytes.Equal(a, b) {
+		t.Fatal(a, "!=", b)
+	}
+}
+
 func TestNoiseHandshake(t *testing.T) {
 	dev1 := randDevice(t)
 	dev2 := randDevice(t)
diff --git a/device/tun_test.go b/device/tun_test.go
deleted file mode 100644
index 2ccae62..0000000
--- a/device/tun_test.go
+++ /dev/null
@@ -1,56 +0,0 @@
-/* SPDX-License-Identifier: MIT
- *
- * Copyright (C) 2017-2021 WireGuard LLC. All Rights Reserved.
- */
-
-package device
-
-import (
-	"errors"
-	"os"
-
-	"golang.zx2c4.com/wireguard/tun"
-)
-
-// newDummyTUN creates a dummy TUN device with the specified name.
-func newDummyTUN(name string) tun.Device {
-	return &dummyTUN{
-		name:    name,
-		packets: make(chan []byte, 100),
-		events:  make(chan tun.Event, 10),
-	}
-}
-
-// A dummyTUN is a tun.Device which is used in unit tests.
-type dummyTUN struct {
-	name    string
-	mtu     int
-	packets chan []byte
-	events  chan tun.Event
-}
-
-func (d *dummyTUN) Events() chan tun.Event { return d.events }
-func (*dummyTUN) File() *os.File           { return nil }
-func (*dummyTUN) Flush() error             { return nil }
-func (d *dummyTUN) MTU() (int, error)      { return d.mtu, nil }
-func (d *dummyTUN) Name() (string, error)  { return d.name, nil }
-
-func (d *dummyTUN) Close() error {
-	close(d.events)
-	close(d.packets)
-	return nil
-}
-
-func (d *dummyTUN) Read(b []byte, offset int) (int, error) {
-	buf, ok := <-d.packets
-	if !ok {
-		return 0, errors.New("device closed")
-	}
-	copy(b[offset:], buf)
-	return len(buf), nil
-}
-
-func (d *dummyTUN) Write(b []byte, offset int) (int, error) {
-	d.packets <- b[offset:]
-	return len(b), nil
-}