diff --git a/CHANGES.rst b/CHANGES.rst
index 1be703e..f02942c 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -1,6 +1,12 @@
 Changelog
 =========
 
+4.0.1 (unreleased)
+------------------
+
+- Nothing changed yet.
+
+
 4.0 (2024-10-24)
 ----------------
 
diff --git a/setup.py b/setup.py
index 446b054..7e75c70 100644
--- a/setup.py
+++ b/setup.py
@@ -22,7 +22,7 @@
 
 setup(
     name='Products.GenericSetup',
-    version='4.0',
+    version='4.0.1.dev0',
     description='Read Zope configuration state from profile dirs / tarballs',
     long_description=README + _BOUNDARY + CHANGES,
     classifiers=[