diff --git a/docs/source/_static/rest-api.yml b/docs/source/_static/rest-api.yml
index 836543d0..b611f870 100644
--- a/docs/source/_static/rest-api.yml
+++ b/docs/source/_static/rest-api.yml
@@ -6,7 +6,7 @@ info:
   description: The REST API for JupyterHub
   license:
     name: BSD-3-Clause
-  version: 4.1.0.dev
+  version: 5.0.0.dev
 servers:
   - url: /hub/api
 security:
diff --git a/jupyterhub/_version.py b/jupyterhub/_version.py
index 95f2026a..5a92d9ec 100644
--- a/jupyterhub/_version.py
+++ b/jupyterhub/_version.py
@@ -2,7 +2,7 @@
 # Copyright (c) Jupyter Development Team.
 # Distributed under the terms of the Modified BSD License.
 # version_info updated by running `tbump`
-version_info = (4, 1, 0, "", "dev")
+version_info = (5, 0, 0, "", "dev")
 
 # pep 440 version: no dot before beta/rc, but before .dev
 # 0.1.0rc1
diff --git a/pyproject.toml b/pyproject.toml
index 84eabed9..4b99b533 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -7,7 +7,7 @@ build-backend = "setuptools.build_meta"
 # ref: https://setuptools.pypa.io/en/latest/userguide/pyproject_config.html
 [project]
 name = "jupyterhub"
-version = "4.1.0.dev"
+version = "5.0.0.dev"
 dynamic = ["readme", "dependencies"]
 description = "JupyterHub: A multi-user server for Jupyter notebooks"
 authors = [
@@ -140,7 +140,7 @@ target_version = [
 github_url = "https://github.com/jupyterhub/jupyterhub"
 
 [tool.tbump.version]
-current = "4.1.0.dev"
+current = "5.0.0.dev"
 
 # Example of a semver regexp.
 # Make sure this matches current_version before