diff --git a/include/dragonbox/dragonbox_to_chars.h b/include/dragonbox/dragonbox_to_chars.h
index fa58098..da18dfe 100644
--- a/include/dragonbox/dragonbox_to_chars.h
+++ b/include/dragonbox/dragonbox_to_chars.h
@@ -1,4 +1,4 @@
-// Copyright 2020-2021 Junekey Jeon
+// Copyright 2020-2022 Junekey Jeon
 //
 // The contents of this file may be used under the terms of
 // the Apache License v2.0 with LLVM Exceptions.
diff --git a/source/dragonbox_to_chars.cpp b/source/dragonbox_to_chars.cpp
index 21d6729..30898da 100644
--- a/source/dragonbox_to_chars.cpp
+++ b/source/dragonbox_to_chars.cpp
@@ -1,4 +1,4 @@
-// Copyright 2020-2021 Junekey Jeon
+// Copyright 2020-2022 Junekey Jeon
 //
 // The contents of this file may be used under the terms of
 // the Apache License v2.0 with LLVM Exceptions.
diff --git a/subproject/common/source/big_uint.cpp b/subproject/common/source/big_uint.cpp
index f7650ba..38dcdbd 100644
--- a/subproject/common/source/big_uint.cpp
+++ b/subproject/common/source/big_uint.cpp
@@ -1,3 +1,20 @@
+// Copyright 2022 Junekey Jeon
+//
+// The contents of this file may be used under the terms of
+// the Apache License v2.0 with LLVM Exceptions.
+//
+//    (See accompanying file LICENSE-Apache or copy at
+//     https://llvm.org/foundation/relicensing/LICENSE.txt)
+//
+// Alternatively, the contents of this file may be used under the terms of
+// the Boost Software License, Version 1.0.
+//    (See accompanying file LICENSE-Boost or copy at
+//     https://www.boost.org/LICENSE_1_0.txt)
+//
+// Unless required by applicable law or agreed to in writing, this software
+// is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.
+
 #include "big_uint.h"
 #include "dragonbox/dragonbox.h"
 #include <cassert>