diff --git a/CHANGES.txt b/CHANGES.txt
index 7ad3609..5fbd210 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -1,6 +1,10 @@
 Changelog
 =========
 
+3.3 (unreleased)
+----------------
+
+
 3.2 (2021-03-16)
 ----------------
 - Add support for Python 3.9
diff --git a/setup.py b/setup.py
index 9e494e4..d3b096f 100644
--- a/setup.py
+++ b/setup.py
@@ -17,7 +17,7 @@
 
 
 setup(name='Products.MIMETools',
-      version='3.2',
+      version='3.3.dev0',
       url='https://github.com/zopefoundation/Products.MIMETools',
       project_urls={
         'Issue Tracker': ('https://github.com/zopefoundation'