diff --git a/net/dnscache/dnscache_test.go b/net/dnscache/dnscache_test.go
index e6969da14..96e1cc8a5 100644
--- a/net/dnscache/dnscache_test.go
+++ b/net/dnscache/dnscache_test.go
@@ -1,3 +1,7 @@
+// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
 package dnscache
 
 import (