diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
index 0000000..12f84c2
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,17 @@
+
+# Changelog
+All notable changes to rattail-tempmon will be documented in this file.
+
+The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
+and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
+
+## v0.4.0 (2024-06-10)
+
+### Feat
+
+- switch from setup.cfg to pyproject.toml + hatchling
+
+
+## Older Releases
+
+Please see `docs/OLDCHANGES.rst` for older release notes.
diff --git a/CHANGES.rst b/docs/OLDCHANGES.rst
similarity index 97%
rename from CHANGES.rst
rename to docs/OLDCHANGES.rst
index eba4936..8727078 100644
--- a/CHANGES.rst
+++ b/docs/OLDCHANGES.rst
@@ -2,6 +2,10 @@
 CHANGELOG
 =========
 
+NB. this file contains "old" release notes only.  for newer releases
+see the `CHANGELOG.md` file in the source root folder.
+
+
 0.3.0 (2024-05-30)
 ------------------
 
diff --git a/pyproject.toml b/pyproject.toml
index b5920ba..a0d9937 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -6,7 +6,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "rattail-tempmon"
-version = "0.3.0"
+version = "0.4.0"
 description = "Retail Software Framework - Temperature monitoring add-on"
 readme = "README.rst"
 authors = [{name = "Lance Edgar", email = "lance@edbob.org"}]