diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 99e039dc..2c7e915a 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -16,6 +16,7 @@ jobs:
           - {VERSION: "3.10", TOXENV: "py310"}
           - {VERSION: "3.11", TOXENV: "py311"}
           - {VERSION: "3.12", TOXENV: "py312"}
+          - {VERSION: "3.13-dev", TOXENV: "py313"}
           - {VERSION: "pypy-3.9", TOXENV: "pypy3"}
           - {VERSION: "pypy-3.10", TOXENV: "pypy3"}
           - {VERSION: "3.11", TOXENV: "py311-useWheel", OS: "windows-2022" }
@@ -26,6 +27,7 @@ jobs:
           - {VERSION: "3.10", TOXENV: "py310-cryptographyMain"}
           - {VERSION: "3.11", TOXENV: "py311-cryptographyMain"}
           - {VERSION: "3.12", TOXENV: "py312-cryptographyMain"}
+          - {VERSION: "3.13-dev", TOXENV: "py313-cryptographyMain"}
           - {VERSION: "pypy-3.9", TOXENV: "pypy3-cryptographyMain"}
           - {VERSION: "pypy-3.10", TOXENV: "pypy3-cryptographyMain"}
           # -cryptographyMinimum
@@ -35,6 +37,7 @@ jobs:
           - {VERSION: "3.10", TOXENV: "py310-cryptographyMinimum"}
           - {VERSION: "3.11", TOXENV: "py311-cryptographyMinimum"}
           - {VERSION: "3.12", TOXENV: "py312-cryptographyMinimum"}
+          - {VERSION: "3.13-dev", TOXENV: "py313-cryptographyMinimum"}
           - {VERSION: "pypy-3.10", TOXENV: "pypy3-cryptographyMinimum"}
           # Cryptography wheels
           - {VERSION: "3.9", TOXENV: "py39-cryptographyMinimum-useWheel"}
diff --git a/setup.py b/setup.py
index 5397af58..37c0fa26 100644
--- a/setup.py
+++ b/setup.py
@@ -83,6 +83,7 @@ def find_meta(meta):
             "Programming Language :: Python :: 3.10",
             "Programming Language :: Python :: 3.11",
             "Programming Language :: Python :: 3.12",
+            "Programming Language :: Python :: 3.13",
             "Programming Language :: Python :: Implementation :: CPython",
             "Programming Language :: Python :: Implementation :: PyPy",
             "Topic :: Security :: Cryptography",
diff --git a/tox.ini b/tox.ini
index 8aba4df9..9e2da1d8 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,5 +1,5 @@
 [tox]
-envlist = py{py3,37,38,39,310,311,312}{,-cryptographyMinimum}{,-useWheel}{,-randomorder},py311-twistedTrunk,check-manifest,lint,py311-mypy,docs,coverage-report
+envlist = py{py3,37,38,39,310,311,312,313}{,-cryptographyMinimum}{,-useWheel}{,-randomorder},py311-twistedTrunk,check-manifest,lint,py311-mypy,docs,coverage-report
 
 [testenv]
 allowlist_externals =