diff --git a/core/device/tun/opts.go b/core/device/tun/opts.go
deleted file mode 100755
index b1a474a..0000000
--- a/core/device/tun/opts.go
+++ /dev/null
@@ -1,15 +0,0 @@
-package tun
-
-type Option func(*TUN)
-
-func WithName(name string) Option {
-	return func(t *TUN) {
-		t.name = name
-	}
-}
-
-func WithMTU(mtu uint32) Option {
-	return func(t *TUN) {
-		t.mtu = mtu
-	}
-}
diff --git a/core/device/tun/tun_gvisor.go b/core/device/tun/tun_gvisor.go
index 6a36c46..b00f8da 100755
--- a/core/device/tun/tun_gvisor.go
+++ b/core/device/tun/tun_gvisor.go
@@ -23,12 +23,8 @@ type TUN struct {
 	name string
 }
 
-func Open(opts ...Option) (device.Device, error) {
-	t := &TUN{}
-
-	for _, opt := range opts {
-		opt(t)
-	}
+func Open(name string, mtu uint32) (device.Device, error) {
+	t := &TUN{name: name, mtu: mtu}
 
 	if len(t.name) >= unix.IFNAMSIZ {
 		return nil, fmt.Errorf("interface name too long: %s", t.name)
@@ -46,11 +42,11 @@ func Open(opts ...Option) (device.Device, error) {
 		}
 	}
 
-	mtu, err := rawfile.GetMTU(t.name)
+	_mtu, err := rawfile.GetMTU(t.name)
 	if err != nil {
 		return nil, fmt.Errorf("get mtu: %w", err)
 	}
-	t.mtu = mtu
+	t.mtu = _mtu
 
 	ep, err := fdbased.New(&fdbased.Options{
 		MTU: t.mtu,
diff --git a/core/device/tun/tun_wireguard.go b/core/device/tun/tun_wireguard.go
index 500ac6c..feeffbd 100755
--- a/core/device/tun/tun_wireguard.go
+++ b/core/device/tun/tun_wireguard.go
@@ -19,12 +19,8 @@ type TUN struct {
 	name string
 }
 
-func Open(opts ...Option) (device.Device, error) {
-	t := &TUN{}
-
-	for _, opt := range opts {
-		opt(t)
-	}
+func Open(name string, mtu uint32) (device.Device, error) {
+	t := &TUN{name: name, mtu: mtu}
 
 	forcedMTU := defaultMTU
 	if t.mtu > 0 {
@@ -37,11 +33,11 @@ func Open(opts ...Option) (device.Device, error) {
 	}
 	t.nt = nt.(*tun.NativeTun)
 
-	mtu, err := nt.MTU()
+	_mtu, err := nt.MTU()
 	if err != nil {
 		return nil, fmt.Errorf("get mtu: %w", err)
 	}
-	t.mtu = uint32(mtu)
+	t.mtu = uint32(_mtu)
 
 	ep, err := rwbased.New(t, t.mtu)
 	if err != nil {
diff --git a/engine/parse.go b/engine/parse.go
index 24e60e1..bef45ae 100644
--- a/engine/parse.go
+++ b/engine/parse.go
@@ -27,7 +27,7 @@ func parseDevice(s string, mtu uint32) (device.Device, error) {
 
 	switch driver {
 	case tun.Driver:
-		return tun.Open(tun.WithName(name), tun.WithMTU(mtu))
+		return tun.Open(name, mtu)
 	default:
 		return nil, fmt.Errorf("unsupported driver: %s", driver)
 	}