diff --git a/CHANGES.rst b/CHANGES.rst
index e8ffa4c..366def7 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -1,6 +1,10 @@
 Change log
 ==========
 
+4.3 (unreleased)
+----------------
+
+
 4.2 (2023-12-28)
 ----------------
 
diff --git a/setup.py b/setup.py
index 0da7667..4dbf34d 100644
--- a/setup.py
+++ b/setup.py
@@ -21,7 +21,7 @@ def _read(name):
 
 
 setup(name='Products.mcdutils',
-      version='4.2',
+      version='4.3.dev0',
       description=('A Zope product with memcached-backed ZCache and '
                    'Zope session implementations.'),
       long_description=_read('README.rst') + '\n\n' + _read('CHANGES.rst'),