diff --git a/README.md b/README.md
index b76601e0..3228028e 100644
--- a/README.md
+++ b/README.md
@@ -17,7 +17,7 @@ To use the Mollie API client, the following things are required:
 + Create a new [Website profile](https://www.mollie.com/dashboard/settings/profiles) to generate API keys and setup your webhook.
 + Now you're ready to use the Mollie API client in test mode.
 + Follow [a few steps](https://www.mollie.com/dashboard/?modal=onboarding) to enable payment methods in live mode, and let us handle the rest.
-+ Python >= 3.8
++ Python >= 3.10
 + Up-to-date OpenSSL (or other SSL/TLS toolkit)
 + Mollie API client for Python has a dependency on [Requests](http://docs.python-requests.org/en/master/) and [Requests-OAuthlib](https://requests-oauthlib.readthedocs.io/en/latest/)
 
@@ -25,7 +25,8 @@ To use the Mollie API client, the following things are required:
 If your application uses a recent v2 version of the Mollie API client and you're ready to migrate to v3, [read all about the API changes](https://github.com/mollie/mollie-api-python/blob/main/v3-api-changes.md) that we made. Use the docs to quickly find how to update your integration code and use the v3 client correctly.
 
 ## Installation
-**Please note:** If you want to install an older version of the Mollie API client (current major version is `v3`), then please refer to their respective github branches for installation instructions:
+**Please note:** If you want to install an older version of the Mollie API client (current major version is `v4`), then please refer to their respective github branches for installation instructions:
+- version 3.x.x is available from the [v3-develop branch](https://github.com/mollie/mollie-api-python/tree/v3-develop)
 - version 2.x.x is available from the [v2-develop branch](https://github.com/mollie/mollie-api-python/tree/v2-develop).
 - version 1.x.x is available from the [v1-develop branch](https://github.com/mollie/mollie-api-python/tree/v1-develop).
 
@@ -35,7 +36,7 @@ $ pip install mollie-api-python
 ```
 You may also git checkout or [download all the files](https://github.com/mollie/mollie-api-python/archive/main.zip), and include the Mollie API client manually.
 
-Create and activate a Python >= 3.8 virtual environment (inside a git checkout or downloaded archive).
+Create and activate a Python >= 3.10 virtual environment (inside a git checkout or downloaded archive).
 
 ```shell
 $ cd mollie-api-python
diff --git a/mollie/api/version.py b/mollie/api/version.py
index ca7ed7de..6e062049 100644
--- a/mollie/api/version.py
+++ b/mollie/api/version.py
@@ -4,4 +4,4 @@
 # processed by python imports and by regular expressions. The version is defined as a string in the
 # regular semantic versioning scheme (major, minor, patch) as defined by PEP 440.
 
-VERSION = "3.9.1"
+VERSION = "4.0.0"
diff --git a/pyproject.toml b/pyproject.toml
index cd477b95..78159625 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [tool.black]
 line-length = 119
-target-version = ['py38']
+target-version = ['py310']
 
 [tool.isort]
 profile = "black"
@@ -25,7 +25,7 @@ exclude_lines = [
 
 [tool.tox]
 requires = ["tox>=4.19"]
-env_list = ["flake8", "3.12", "3.11", "3.10", "3.9", "3.8", "type"]
+env_list = ["flake8", "3.12", "3.11", "3.10", "type"]
 
 [tool.tox.env_run_base]
 description = "Run tests under {base_python}"