diff --git a/.github/workflows/build-release.yml b/.github/workflows/build-release.yml
index 59b52e5a..c3ec62ed 100644
--- a/.github/workflows/build-release.yml
+++ b/.github/workflows/build-release.yml
@@ -11,9 +11,9 @@ jobs:
       matrix:
         include:
           - { name: "3.8", python: "3.8", tox: py38-marshmallow3 }
-          - { name: "3.11", python: "3.11", tox: py311-marshmallow3 }
+          - { name: "3.12", python: "3.11", tox: py312-marshmallow3 }
           - { name: "lowest", python: "3.8", tox: py38-lowest }
-          - { name: "dev", python: "3.11", tox: py311-marshmallowdev }
+          - { name: "dev", python: "3.12", tox: py312-marshmallowdev }
     steps:
       - uses: actions/checkout@v3.1.0
       - uses: actions/setup-python@v4.3.0
diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index 11a9a097..dfede15e 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -1,6 +1,13 @@
 Changelog
 ---------
 
+0.31.0 (unreleased)
++++++++++++++++++++
+
+Other changes:
+
+* Support Python 3.12.
+
 0.30.0 (2024-01-07)
 +++++++++++++++++++
 
diff --git a/pyproject.toml b/pyproject.toml
new file mode 100644
index 00000000..4c6215c0
--- /dev/null
+++ b/pyproject.toml
@@ -0,0 +1,3 @@
+[tool.black]
+line-length = 88
+target-version = ['py38', 'py39', 'py310', 'py311', 'py312']
diff --git a/setup.cfg b/setup.cfg
index c162b23d..faf7101f 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -1,9 +1,11 @@
-[bdist_wheel]
-# This flag says that the code is written to work on both Python 2 and Python
-# 3. If at all possible, it is good practice to do this. If you cannot, you
-# will need to generate wheels for each Python version that you support.
-universal=1
+[metadata]
+license_files = LICENSE
 
 [flake8]
-max-line-length = 88
-extend-ignore = E203, E501
+max-line-length = 90
+max-complexity = 18
+extend-ignore = E203, E266, E501, E731, B903
+
+[tool:pytest]
+norecursedirs = .git .ropeproject .tox docs env venv tests/mypy_test_cases
+addopts = -v --tb=short
diff --git a/setup.py b/setup.py
index a410b2b5..189028fc 100644
--- a/setup.py
+++ b/setup.py
@@ -75,6 +75,7 @@ def read(fname):
         "Programming Language :: Python :: 3.9",
         "Programming Language :: Python :: 3.10",
         "Programming Language :: Python :: 3.11",
+        "Programming Language :: Python :: 3.12",
     ],
     test_suite="tests",
     project_urls={
diff --git a/tox.ini b/tox.ini
index fdc22955..2898d9ad 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,8 +1,8 @@
 [tox]
 envlist=
     lint
-    py{38,39,310,311}-marshmallow3
-    py311-marshmallowdev
+    py{38,39,310,311,312}-marshmallow3
+    py312-marshmallowdev
     py38-lowest
     docs