diff --git a/src/kernel/arch/x86_64/serial.rs b/src/kernel/arch/x86_64/serial.rs
index e2d38f2..9f15467 100644
--- a/src/kernel/arch/x86_64/serial.rs
+++ b/src/kernel/arch/x86_64/serial.rs
@@ -1,3 +1,5 @@
+// Copyright (c) 2025 shibedrill
+// SPDX-License-Identifier: GPL-3.0-or-later
 
 use crate::{asm::*, log::LogSubscriber};