diff --git a/.github/workflows/python-nightly.yml b/.github/workflows/python-nightly.yml
index 8e5ade8ae..feaded46d 100644
--- a/.github/workflows/python-nightly.yml
+++ b/.github/workflows/python-nightly.yml
@@ -49,6 +49,7 @@ jobs:
           # https://launchpad.net/~deadsnakes/+archive/ubuntu/nightly/+packages
           - "3.11-dev"
           - "3.12-dev"
+          - "3.13-dev"
           # https://github.com/actions/setup-python#available-versions-of-pypy
           - "pypy-3.8-nightly"
           - "pypy-3.9-nightly"
diff --git a/tox.ini b/tox.ini
index 51fe5828c..71ee4a18e 100644
--- a/tox.ini
+++ b/tox.ini
@@ -4,7 +4,7 @@
 [tox]
 # When changing this list, be sure to check the [gh] list below.
 # PYVERSIONS
-envlist = py{38,39,310,311,312}, pypy3, doc, lint, mypy
+envlist = py{38,39,310,311,312,313}, pypy3, doc, lint, mypy
 skip_missing_interpreters = {env:COVERAGE_SKIP_MISSING_INTERPRETERS:True}
 toxworkdir = {env:TOXWORKDIR:.tox}
 
@@ -122,4 +122,5 @@ python =
     3.10 = py310
     3.11 = py311
     3.12 = py312
+    3.13 = py313
     pypy-3 = pypy3