diff --git a/src/runtime/lockrank_off.go b/src/runtime/lockrank_off.go
index 891589c0f2..425ca8dd93 100644
--- a/src/runtime/lockrank_off.go
+++ b/src/runtime/lockrank_off.go
@@ -1,3 +1,7 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
 // +build !goexperiment.staticlockranking
 
 package runtime
diff --git a/src/runtime/lockrank_on.go b/src/runtime/lockrank_on.go
index cf4151ff46..fbc5ff58b7 100644
--- a/src/runtime/lockrank_on.go
+++ b/src/runtime/lockrank_on.go
@@ -1,3 +1,7 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
 // +build goexperiment.staticlockranking
 
 package runtime
diff --git a/src/sync/runtime2.go b/src/sync/runtime2.go
index 931edad9f1..f10c4e8e0e 100644
--- a/src/sync/runtime2.go
+++ b/src/sync/runtime2.go
@@ -1,3 +1,7 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
 // +build !goexperiment.staticlockranking
 
 package sync
diff --git a/src/sync/runtime2_lockrank.go b/src/sync/runtime2_lockrank.go
index 5a68e901fa..aaa1c27626 100644
--- a/src/sync/runtime2_lockrank.go
+++ b/src/sync/runtime2_lockrank.go
@@ -1,3 +1,7 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
 // +build goexperiment.staticlockranking
 
 package sync