I have made a copy of an open source project that is licensed under the Apache 2.0 license, and I have made modifications to some of its files. I want to release my modified version to the general public.

According to the Apache 2.0 license clause 4(b):

You must cause any modified files to carry prominent notices stating that You changed the files; and

How do I comply with the requirement to "carry prominent notices"?

All the files I modified have this header written by the original author of the project:

 * Copyright 2018 Acme Corporation
 * 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,
 * See the License for the specific language governing permissions and
 * limitations under the License.

What exactly do I add to this header such that it will carry a "prominent notice" that I have changed the file?

1 Answer 1


Generally, adding your own copyright line is considered to be a prominent enough notice that you modified the file.

Thus, add a line Copyright 2022 Flux next to the existing line(s) that have the same form.

  • "Thus, add a line Copyright 2022 Flux next to the existing line(s) that have the same form" — Would that be above or below the Copyright 2018 Acme Corporation line?
    – Flux
    Commented Aug 28, 2022 at 5:46
  • 2
    Either side is good. I like to have the years in chronological order, so I would put it below. If there are already multiple copyright lines, keep the years in the same order. Commented Aug 28, 2022 at 6:22
  • I found a related question Satisfying Apache 2.0 section 4.(b) when forking a project, but I don't think the answer there is correct.
    – Flux
    Commented Aug 28, 2022 at 14:28

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