diff --git a/.github/workflows/post-release-mergeback.yml b/.github/workflows/post-release-mergeback.yml
index c3d0b291a..3e3e80250 100644
--- a/.github/workflows/post-release-mergeback.yml
+++ b/.github/workflows/post-release-mergeback.yml
@@ -133,8 +133,8 @@ jobs:
           # Update the version number ready for the next release
           npm version patch --no-git-tag-version
 
-          # Update the changelog
-          perl -i -pe 's/^/## \[UNRELEASED\]\n\nNo user facing changes.\n\n/ if($.==5)' CHANGELOG.md
+          # Update the changelog, adding a new version heading directly above the most recent existing one
+          awk '!f && /##/{print "'"## [UNRELEASED]\n\nNo user facing changes.\n"'"; f=1}1' CHANGELOG.md > temp && mv temp CHANGELOG.md
           git add .
           git commit -m "Update changelog and version after ${VERSION}"
 
diff --git a/CHANGELOG.md b/CHANGELOG.md
index bd34fabfd..b3d0ac2c5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,8 @@
 
 See the [releases page](https://github.com/github/codeql-action/releases) for the relevant changes to the CodeQL CLI and language packs.
 
+Note that the only difference between `v2` and `v3` of the CodeQL Action is the node version they support, with `v3` running on node 20 while we continue to release `v2` to support running on node 16. For example `3.22.11` was the first `v3` release and is functionally identical to `2.22.11`. This approach ensures an easy way to track exactly which features are included in different versions, indicated by the minor and patch version numbers.
+
 ## [UNRELEASED]
 
 No user facing changes.