diff --git a/benchmarks/check_threshold.py b/benchmarks/check_threshold.py
index bc5f682b..31f48c3a 100644
--- a/benchmarks/check_threshold.py
+++ b/benchmarks/check_threshold.py
@@ -1,3 +1,17 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+#
+# 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.
+
 import argparse
 
 import pandas as pd
diff --git a/opacus/accountants/analysis/prv/compose.py b/opacus/accountants/analysis/prv/compose.py
index 04aecf5b..675efae0 100644
--- a/opacus/accountants/analysis/prv/compose.py
+++ b/opacus/accountants/analysis/prv/compose.py
@@ -1,3 +1,17 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+#
+# 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.
+
 from typing import List
 
 import numpy as np
diff --git a/opacus/accountants/analysis/prv/domain.py b/opacus/accountants/analysis/prv/domain.py
index 220dbbd9..2e15998d 100644
--- a/opacus/accountants/analysis/prv/domain.py
+++ b/opacus/accountants/analysis/prv/domain.py
@@ -1,3 +1,17 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+#
+# 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.
+
 from dataclasses import dataclass
 from typing import Sequence
 
diff --git a/opacus/accountants/analysis/prv/prvs.py b/opacus/accountants/analysis/prv/prvs.py
index 9650b759..b4ffcf76 100644
--- a/opacus/accountants/analysis/prv/prvs.py
+++ b/opacus/accountants/analysis/prv/prvs.py
@@ -1,3 +1,17 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+#
+# 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.
+
 from dataclasses import dataclass
 from typing import Tuple
 
diff --git a/opacus/grad_sample/functorch.py b/opacus/grad_sample/functorch.py
index 956141ff..b74f87b1 100644
--- a/opacus/grad_sample/functorch.py
+++ b/opacus/grad_sample/functorch.py
@@ -1,3 +1,17 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+#
+# 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.
+
 import copy
 
 import torch
diff --git a/opacus/tests/privacy_engine_validation_test.py b/opacus/tests/privacy_engine_validation_test.py
index 04138a43..151176d1 100644
--- a/opacus/tests/privacy_engine_validation_test.py
+++ b/opacus/tests/privacy_engine_validation_test.py
@@ -1,3 +1,17 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+#
+# 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.
+
 import unittest
 
 import torch
diff --git a/opacus/tests/utils.py b/opacus/tests/utils.py
index 36833977..a2c9a5ec 100644
--- a/opacus/tests/utils.py
+++ b/opacus/tests/utils.py
@@ -1,3 +1,17 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+#
+# 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.
+
 import torch
 import torch.nn as nn
 import torch.nn.functional as F