diff --git a/CHANGES.rst b/CHANGES.rst
index 8193112..6abcb9d 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -3,6 +3,10 @@ Changelog
 
 For changes before version 3.0, see ``HISTORY.rst``.
 
+5.7 (unreleased)
+----------------
+
+
 5.6 (2022-11-03)
 ----------------
 
diff --git a/setup.py b/setup.py
index 4c18642..bf16403 100644
--- a/setup.py
+++ b/setup.py
@@ -32,7 +32,7 @@
                  join('include', 'Acquisition', 'Acquisition.h')]),
 ]
 
-version = '5.6'
+version = '5.7.dev0'
 
 
 setup(name='AccessControl',