diff --git a/osbase/net/dns/metrics.go b/osbase/net/dns/metrics.go
index 13d046a..81789dd 100644
--- a/osbase/net/dns/metrics.go
+++ b/osbase/net/dns/metrics.go
@@ -1,3 +1,6 @@
+// Copyright The Monogon Project Authors.
+// SPDX-License-Identifier: Apache-2.0
+
 package dns
 
 import (