diff --git a/go/net/psample/psample_test.go b/go/net/psample/psample_test.go
index b01ad97..6be8b4e 100644
--- a/go/net/psample/psample_test.go
+++ b/go/net/psample/psample_test.go
@@ -1,3 +1,6 @@
+// Copyright The Monogon Project Authors.
+// SPDX-License-Identifier: Apache-2.0
+
 // This test requires the following Linux kernel configuration options to be
 // set:
 //