diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 0f38b0291..e3f1e83df 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -47,7 +47,7 @@ jobs:
         include:
           # On macOS don't bother with 3.8, just to get faster builds.
           - os: macos-12
-            python-version: "3.9"
+            python-version: "3.12"
           - os: macos-12
             python-version: "3.11"
           # We only support PyPy on Linux at the moment.
@@ -55,6 +55,8 @@ jobs:
             python-version: "pypy-3.8"
           - os: ubuntu-latest
             python-version: "pypy-3.9"
+          - os: ubuntu-latest
+            python-version: "3.12"
 
     steps:
       # See https://github.com/actions/checkout. A fetch-depth of 0
@@ -169,7 +171,7 @@ jobs:
           - false
         include:
           - os: ubuntu-20.04
-            python-version: "3.10"
+            python-version: "3.12"
             force-foolscap: true
     steps:
 
diff --git a/tox.ini b/tox.ini
index 11daa75fe..a23fc1a6a 100644
--- a/tox.ini
+++ b/tox.ini
@@ -11,6 +11,7 @@ python =
     3.9: py39-coverage
     3.10: py310-coverage
     3.11: py311-coverage
+    3.12: py312-coverage
     pypy-3.8: pypy38
     pypy-3.9: pypy39
 
@@ -18,7 +19,7 @@ python =
 twisted = 1
 
 [tox]
-envlist = typechecks,codechecks,py{38,39,310,311}-{coverage},pypy27,pypy38,pypy39,integration
+envlist = typechecks,codechecks,py{38,39,310,311,312}-{coverage},pypy27,pypy38,pypy39,integration
 minversion = 2.4
 
 [testenv]