diff --git a/docs/HISTORY.txt b/docs/HISTORY.txt
index a8df7fa..091c669 100644
--- a/docs/HISTORY.txt
+++ b/docs/HISTORY.txt
@@ -2,6 +2,12 @@ Changelog
 =========
 
 
+3.3.1 (unreleased)
+------------------
+
+- Nothing changed yet.
+
+
 3.3.0 (2022-03-28)
 ------------------
 
diff --git a/setup.py b/setup.py
index f6b55ce..11898ad 100644
--- a/setup.py
+++ b/setup.py
@@ -1,7 +1,7 @@
 from setuptools import setup, find_packages
 import os
 
-version = '3.3.0'
+version = '3.3.1.dev0'
 
 tests_require = [
     'ftw.testing >= 2.0.0.dev0',