diff --git a/alts/src/main/proto/grpc/gcp/altscontext.proto b/alts/src/main/proto/grpc/gcp/altscontext.proto
index 30cc082728..48c2d6abd8 100644
--- a/alts/src/main/proto/grpc/gcp/altscontext.proto
+++ b/alts/src/main/proto/grpc/gcp/altscontext.proto
@@ -1,9 +1,23 @@
+// Copyright 2018 gRPC authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
 syntax = "proto3";
 
-import "grpc/gcp/transport_security_common.proto";
-
 package grpc.gcp;
 
+import "grpc/gcp/transport_security_common.proto";
+
 option java_package = "io.grpc.alts.internal";
 
 message AltsContext {
diff --git a/alts/src/main/proto/grpc/gcp/handshaker.proto b/alts/src/main/proto/grpc/gcp/handshaker.proto
index feffe1f2a0..b56f07113f 100644
--- a/alts/src/main/proto/grpc/gcp/handshaker.proto
+++ b/alts/src/main/proto/grpc/gcp/handshaker.proto
@@ -1,9 +1,23 @@
+// Copyright 2018 gRPC authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
 syntax = "proto3";
 
-import "grpc/gcp/transport_security_common.proto";
-
 package grpc.gcp;
 
+import "grpc/gcp/transport_security_common.proto";
+
 option java_package = "io.grpc.alts.internal";
 
 enum HandshakeProtocol {
diff --git a/alts/src/main/proto/grpc/gcp/transport_security_common.proto b/alts/src/main/proto/grpc/gcp/transport_security_common.proto
index 70c0909589..d0f861e644 100644
--- a/alts/src/main/proto/grpc/gcp/transport_security_common.proto
+++ b/alts/src/main/proto/grpc/gcp/transport_security_common.proto
@@ -1,3 +1,17 @@
+// Copyright 2018 gRPC authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
 syntax = "proto3";
 
 package grpc.gcp;