diff --git a/CHANGES.rst b/CHANGES.rst
index 55a725f..ff03318 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -2,6 +2,12 @@
  Changes
 =========
 
+5.2 (unreleased)
+================
+
+- Nothing changed yet.
+
+
 5.1 (2025-02-13)
 ================
 
diff --git a/setup.py b/setup.py
index a32f778..a22eb46 100644
--- a/setup.py
+++ b/setup.py
@@ -34,7 +34,7 @@ def read(*rnames):
 
 setup(
     name='zope.applicationcontrol',
-    version='5.1',
+    version='5.2.dev0',
     author='Zope Foundation and Contributors',
     author_email='zope-dev@zope.dev',
     description='Zope applicationcontrol',