diff --git a/cpp/core/internal/offline_frames_validator.cc b/cpp/core/internal/offline_frames_validator.cc
index b4e9944d..807997e2 100644
--- a/cpp/core/internal/offline_frames_validator.cc
+++ b/cpp/core/internal/offline_frames_validator.cc
@@ -1,3 +1,17 @@
+// Copyright 2020 Google LLC
+//
+// 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
+//
+//     https://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.
+
 #include "core/internal/offline_frames_validator.h"
 
 #include <regex>  //NOLINT
diff --git a/cpp/core/internal/offline_frames_validator.h b/cpp/core/internal/offline_frames_validator.h
index 6cb4f8a5..a673c913 100644
--- a/cpp/core/internal/offline_frames_validator.h
+++ b/cpp/core/internal/offline_frames_validator.h
@@ -1,3 +1,17 @@
+// Copyright 2020 Google LLC
+//
+// 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
+//
+//     https://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.
+
 #ifndef CORE_INTERNAL_OFFLINE_FRAMES_VALIDATOR_H_
 #define CORE_INTERNAL_OFFLINE_FRAMES_VALIDATOR_H_
 
diff --git a/cpp/core/internal/offline_frames_validator_test.cc b/cpp/core/internal/offline_frames_validator_test.cc
index 2fe82049..09fecac4 100644
--- a/cpp/core/internal/offline_frames_validator_test.cc
+++ b/cpp/core/internal/offline_frames_validator_test.cc
@@ -1,3 +1,17 @@
+// Copyright 2020 Google LLC
+//
+// 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
+//
+//     https://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.
+
 #include "core/internal/offline_frames_validator.h"
 
 #include "core/internal/offline_frames.h"