diff --git a/sw/lib/handler.h b/sw/lib/handler.h
index 6c99ef4..6af92d3 100644
--- a/sw/lib/handler.h
+++ b/sw/lib/handler.h
@@ -1,3 +1,7 @@
+// Copyright lowRISC contributors.
+// Licensed under the Apache License, Version 2.0, see LICENSE for details.
+// SPDX-License-Identifier: Apache-2.0
+
 #ifndef _HANDLER_H_
 #define _HANDLER_H_