diff --git a/transport/wireguard/device_system.go b/transport/wireguard/device_system.go
index 1159f568..4e7c65d0 100644
--- a/transport/wireguard/device_system.go
+++ b/transport/wireguard/device_system.go
@@ -82,7 +82,7 @@ func (w *SystemDevice) File() *os.File {
 }
 
 func (w *SystemDevice) Read(bytes []byte, index int) (int, error) {
-	return w.device.Read(bytes[index-tunPacketOffset:])
+	return w.device.Read(bytes[index-tun.PacketOffset:])
 }
 
 func (w *SystemDevice) Write(bytes []byte, index int) (int, error) {
diff --git a/transport/wireguard/tun_darwin.go b/transport/wireguard/tun_darwin.go
deleted file mode 100644
index 112a8825..00000000
--- a/transport/wireguard/tun_darwin.go
+++ /dev/null
@@ -1,3 +0,0 @@
-package wireguard
-
-const tunPacketOffset = 4
diff --git a/transport/wireguard/tun_nondarwin.go b/transport/wireguard/tun_nondarwin.go
deleted file mode 100644
index 0f9c53f1..00000000
--- a/transport/wireguard/tun_nondarwin.go
+++ /dev/null
@@ -1,5 +0,0 @@
-//go:build !darwin
-
-package wireguard
-
-const tunPacketOffset = 0