diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 26f39bd..3e85919 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -9,7 +9,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        python-version: ["3.8", "3.9", "3.10", "3.11"]
+        python-version: ["3.8", "3.9", "3.10", "3.11", "3.12"]
 
         os: [ubuntu-latest]
 
@@ -20,6 +20,7 @@ jobs:
       uses: actions/setup-python@v4
       with:
         python-version: ${{ matrix.python-version }}
+        allow-prereleases: true
 
     - name: Update pip and setuptools
       run: |
diff --git a/DEVELOPMENT.md b/DEVELOPMENT.md
index 0db07f9..7d81dd4 100644
--- a/DEVELOPMENT.md
+++ b/DEVELOPMENT.md
@@ -55,7 +55,7 @@ You can also use [tox](https://tox.wiki/en/latest/index.html) to test with multi
 ```console
 /path/to/venv/bin/tox
 ```
-will by default run all tests on python versions 3.8 through 3.11. If you only want to test a specific version you can specify the environment with `-e`
+will by default run all tests on python versions 3.8 through 3.12. If you only want to test a specific version you can specify the environment with `-e`
 
 ```console
 /path/to/venv/bin/tox -e py38
diff --git a/README.rst b/README.rst
index ddec96a..4bb4317 100644
--- a/README.rst
+++ b/README.rst
@@ -334,6 +334,7 @@ Unreleased
 
 * Fix a crash and several test failures on Python 3.12, all relating to the B907
   check.
+* Declare support for Python 3.12.
 
 23.6.5
 ~~~~~~
diff --git a/pyproject.toml b/pyproject.toml
index e5be03f..f564d70 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -30,6 +30,7 @@ classifiers = [
     "Programming Language :: Python :: 3.9",
     "Programming Language :: Python :: 3.10",
     "Programming Language :: Python :: 3.11",
+    "Programming Language :: Python :: 3.12",
     "Programming Language :: Python :: 3 :: Only",
     "Topic :: Software Development :: Libraries :: Python Modules",
     "Topic :: Software Development :: Quality Assurance",
diff --git a/tox.ini b/tox.ini
index 361c1dc..e27c4fc 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,7 +1,7 @@
 # The test environment and commands
 [tox]
 # default environments to run without `-e`
-envlist = py38, py39, py310, py311
+envlist = py38, py39, py310, py311, py312
 
 [gh-actions]
 python =
@@ -9,8 +9,9 @@ python =
     3.9: py39
     3.10: py310
     3.11: py311
+    3.12: py312
 
-[testenv:{py38, py39, py310, py311}]
+[testenv]
 description = Run coverage
 deps =
     coverage
@@ -19,3 +20,8 @@ deps =
 commands =
     coverage run tests/test_bugbear.py {posargs}
     coverage report -m
+
+[testenv:py312]
+deps =
+    # the other dependencies aren't yet installable on py312+
+    coverage