diff --git a/docs/git/fixing-commits.md b/docs/git/fixing-commits.md
index 018d9ae34e..cfa4463435 100644
--- a/docs/git/fixing-commits.md
+++ b/docs/git/fixing-commits.md
@@ -40,6 +40,30 @@ Sometimes, you want to make one commit out of a bunch of commits. To do this,
 1. `git rebase -i HEAD~n` where `n` is the number of commits you are interested in
 2. Reorder the lines containing the commits and save
 
+## Changing code in an older commit
+
+If your pull request has multiple commits, a reviewer may request changes that require
+you to make changes to an older commit than the latest one. This tends to be more tedious
+than just amending the last commit and there can be various approaches, but the most efficient
+is by using `git commit --fixup`:
+
+1. Make your changes to the files and stage them, as usual.
+1. Identify the hash of the commit you want to modify - for example by copying it from
+   `git log --oneline`.
+1. Commit your changes as a fixup, by using `git commit --fixup <hash of the commit>`.
+1. A new commit with its message starting with `fixup!` has been created. Now you can
+   run `git rebase -i --autosquash HEAD~n`, replacing `n` with the number of commits
+   to include in the rebase, as in the other sections. In the interactive
+   view the commits will be automatically ordered appropriately so that the fixups get
+   squashed into the corresponding commits.
+1. (Optional) If you want to avoid having to include `--autosquash` every time, you
+   can add the following configuration to your `~/.gitconfig`:
+
+   ```
+   [rebase]
+     autosquash = true
+   ```
+
 ## Pushing commits after tidying them
 
 1. `git push origin +my-feature-branch` (Note the `+` there and substitute your actual branch name.)