diff --git a/osbase/msguid/msguid_test.go b/osbase/msguid/msguid_test.go
index b8cdfea..226c7a6 100644
--- a/osbase/msguid/msguid_test.go
+++ b/osbase/msguid/msguid_test.go
@@ -1,3 +1,6 @@
+// Copyright The Monogon Project Authors.
+// SPDX-License-Identifier: Apache-2.0
+
 package msguid
 
 import (