diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7d15430a..fd5a88af 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,6 @@
 # Changelog
 
-## 3.4.2.dev
+## 3.5.0.dev
 
 * Add: option [auth] type oauth2 by code migration from https://gitlab.mim-libre.fr/alphabet/radicale_oauth/-/blob/dev/oauth2/
 * Fix: catch OS errors on PUT MKCOL MKCALENDAR MOVE PROPPATCH (insufficient storage, access denied, internal server error)
diff --git a/pyproject.toml b/pyproject.toml
index eac75049..0f47effb 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -3,7 +3,7 @@ name = "Radicale"
 # When the version is updated, a new section in the CHANGELOG.md file must be
 # added too.
 readme = "README.md"
-version = "3.4.2.dev"
+version = "3.5.0.dev"
 authors = [{name = "Guillaume Ayoub", email = "guillaume.ayoub@kozea.fr"}, {name = "Unrud", email = "unrud@outlook.com"}, {name = "Peter Bieringer", email = "pb@bieringer.de"}]
 license = {text = "GNU GPL v3"}
 description = "CalDAV and CardDAV Server"
diff --git a/setup.py.legacy b/setup.py.legacy
index 09d323a9..aca304f5 100644
--- a/setup.py.legacy
+++ b/setup.py.legacy
@@ -20,7 +20,7 @@ from setuptools import find_packages, setup
 
 # When the version is updated, a new section in the CHANGELOG.md file must be
 # added too.
-VERSION = "3.4.2.dev"
+VERSION = "3.5.0.dev"
 
 with open("README.md", encoding="utf-8") as f:
     long_description = f.read()