diff --git a/src/lib.rs b/src/lib.rs
index 3856931..6bfc485 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -35,9 +35,9 @@ const TTL: u8 = 128;
 #[cfg(unix)]
 const TUN_FLAGS: [u8; 2] = [0x00, 0x00];
 
-#[cfg(any(target_os = "linux", target_os = "freebsd"))]
+#[cfg(target_os = "linux")]
 const TUN_PROTO_IP6: [u8; 2] = [0x86, 0xdd];
-#[cfg(any(target_os = "linux", target_os = "freebsd"))]
+#[cfg(target_os = "linux")]
 const TUN_PROTO_IP4: [u8; 2] = [0x08, 0x00];
 
 #[cfg(target_os = "macos")]