diff --git a/CHANGES b/CHANGES
index c2db0e9134..138dec3db7 100644
--- a/CHANGES
+++ b/CHANGES
@@ -19,6 +19,19 @@ $ pipx install --suffix=@next 'tmuxp' --pip-args '\--pre' --force
 
 <!-- Maintainers, insert changes / features for the next release here -->
 
+_Maintenance only, no bug fixes or features_
+
+## Internal improvements
+
+- Move formatting, import sorting, and linting to [ruff].
+
+  This rust-based checker has dramatically improved performance. Linting and
+  formatting can be done almost instantly.
+
+  This change replaces black, isort, flake8 and flake8 plugins.
+
+[ruff]: https://ruff.rs
+
 ## tmuxp 1.27.1 (2022-04-07)
 
 _Maintenance only, no bug fixes or features_