diff --git a/CHANGES.rst b/CHANGES.rst
index b63daf7..87175e9 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -1,6 +1,12 @@
 ``persistent`` Changelog
 ========================
 
+4.5.1 (unreleased)
+------------------
+
+- Nothing changed yet.
+
+
 4.5.0 (2019-05-09)
 ------------------
 
diff --git a/setup.py b/setup.py
index 9c3682a..93fcdfd 100644
--- a/setup.py
+++ b/setup.py
@@ -19,7 +19,7 @@
 from setuptools import find_packages
 from setuptools import setup
 
-version = '4.5.0'
+version = '4.5.1.dev0'
 
 here = os.path.abspath(os.path.dirname(__file__))