diff --git a/.github/workflows/ci_workflows.yml b/.github/workflows/ci_workflows.yml
index d1e84cb..c62ca70 100644
--- a/.github/workflows/ci_workflows.yml
+++ b/.github/workflows/ci_workflows.yml
@@ -49,16 +49,16 @@ jobs:
             python-version: '3.12'
             toxenv: py312-test-sphinx80
           - os: ubuntu-latest
-            python-version: '3.12'
-            toxenv: py312-test-sphinxdev
+            python-version: '3.13'
+            toxenv: py313-test-sphinxdev
 
           # MacOS X - just the stable and dev
           - os: macos-latest
             python-version: '3.10'
             toxenv: py310-test-sphinx80-clocale
           - os: macos-latest
-            python-version: '3.11'
-            toxenv: py311-test-sphinxdev
+            python-version: '3.13'
+            toxenv: py313-test-sphinxdev
 
           # Windows - just the oldest, stable, and dev
           - os: windows-latest
@@ -68,8 +68,8 @@ jobs:
             python-version: '3.10'
             toxenv: py310-test-sphinx80
           - os: windows-latest
-            python-version: '3.11'
-            toxenv: py311-test-sphinxdev
+            python-version: '3.13'
+            toxenv: py313-test-sphinxdev
 
     steps:
     - uses: actions/checkout@v4
@@ -79,6 +79,7 @@ jobs:
       uses: actions/setup-python@v5
       with:
         python-version: ${{ matrix.python-version }}
+        allow-prereleases: true
     - name: Install graphviz on Linux
       if: startsWith(matrix.os, 'ubuntu')
       run: |
diff --git a/tox.ini b/tox.ini
index c0e74f2..dcf8ab5 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,5 +1,5 @@
 [tox]
-envlist = py{38,39,310,311,312}-test-sphinx{_oldest,53,62,70,71,72,80,dev}{-cov}{-clocale}
+envlist = py{38,39,310,311,312,313}-test-sphinx{_oldest,53,62,70,71,72,80,dev}{-cov}{-clocale}
 requires = pip >= 18.0
            setuptools >= 30.3.0
 isolated_build = true