diff --git a/wgengine/magicsock/magicsock_test.go b/wgengine/magicsock/magicsock_test.go
index 8b13277a6..064343a9b 100644
--- a/wgengine/magicsock/magicsock_test.go
+++ b/wgengine/magicsock/magicsock_test.go
@@ -118,7 +118,7 @@ type magicStack struct {
 	privateKey wgcfg.PrivateKey
 	epCh       chan []string       // endpoint updates produced by this peer
 	conn       *Conn               // the magicsock itself
-	tun        *tuntest.ChannelTUN // tuntap device to send/receive packets
+	tun        *tuntest.ChannelTUN // TUN device to send/receive packets
 	tsTun      *tstun.TUN          // wrapped tun that implements filtering and wgengine hooks
 	dev        *device.Device      // the wireguard-go Device that connects the previous things
 }
diff --git a/wgengine/router/router_default.go b/wgengine/router/router_default.go
index 4dda1ec29..4d7365e04 100644
--- a/wgengine/router/router_default.go
+++ b/wgengine/router/router_default.go
@@ -12,8 +12,8 @@
 	"tailscale.com/types/logger"
 )
 
-func newUserspaceRouter(logf logger.Logf, tunname string, dev *device.Device, tuntap tun.Device, netChanged func()) Router {
-	return NewFakeRouter(logf, tunname, dev, tuntap, netChanged)
+func newUserspaceRouter(logf logger.Logf, tunname string, dev *device.Device, tunDev tun.Device, netChanged func()) Router {
+	return NewFakeRouter(logf, tunname, dev, tunDev, netChanged)
 }
 
 func cleanup(logf logger.Logf, interfaceName string) {
diff --git a/wgengine/userspace.go b/wgengine/userspace.go
index 5bec283eb..973bd23e4 100644
--- a/wgengine/userspace.go
+++ b/wgengine/userspace.go
@@ -48,7 +48,7 @@
 	"tailscale.com/wgengine/tstun"
 )
 
-// minimalMTU is the MTU we set on tailscale's tuntap
+// minimalMTU is the MTU we set on tailscale's TUN
 // interface. wireguard-go defaults to 1420 bytes, which only works if
 // the "outer" MTU is 1500 bytes. This breaks on DSL connections
 // (typically 1492 MTU) and on GCE (1460 MTU?!).
@@ -142,7 +142,7 @@ type EngineConfig struct {
 }
 
 func NewFakeUserspaceEngine(logf logger.Logf, listenPort uint16) (Engine, error) {
-	logf("Starting userspace wireguard engine (FAKE tuntap device).")
+	logf("Starting userspace wireguard engine (with fake TUN device)")
 	conf := EngineConfig{
 		Logf:       logf,
 		TUN:        tstun.NewFakeTUN(),