diff --git a/CHANGES.rst b/CHANGES.rst
index ac7de495b8..bad03ef926 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -8,6 +8,12 @@ https://zope.readthedocs.io/en/2.13/CHANGES.html
 For the change log of the alpha versions see
 https://github.com/zopefoundation/Zope/blob/4.0a6/CHANGES.rst
 
+4.0b10 (unreleased)
+-------------------
+
+- Nothing changed yet.
+
+
 4.0b9 (2019-02-09)
 ------------------
 
diff --git a/setup.py b/setup.py
index 7443e68386..3337a60dc1 100644
--- a/setup.py
+++ b/setup.py
@@ -29,7 +29,7 @@ def _read_file(filename):
 README = _read_file('README.rst')
 CHANGES = _read_file('CHANGES.rst')
 
-version = '4.0b9'
+version = '4.0b10.dev0'
 
 
 setup(