diff --git a/.envrc b/.envrc
index 66f8f02..de78a23 100644
--- a/.envrc
+++ b/.envrc
@@ -2,5 +2,5 @@ if command -v pyenv >/dev/null 2>&1; then
 	layout pyenv $(cat runtimes.txt)
 elif command -v nix >/dev/null 2>&1; then
 	use flake
-	layout python python3.12
+	layout python python3.13
 fi
diff --git a/README.md b/README.md
index fab49b0..fd66290 100644
--- a/README.md
+++ b/README.md
@@ -4,7 +4,7 @@
 
 [![pre-commit](https://github.com/jteppinette/python-logfmter/actions/workflows/pre-commit.yml/badge.svg)](https://github.com/jteppinette/python-logfmter/actions/workflows/pre-commit.yml)
 [![test](https://github.com/jteppinette/python-logfmter/actions/workflows/test.yml/badge.svg)](https://github.com/jteppinette/python-logfmter/actions/workflows/test.yml)
-[![python-3.9-3.10-3.11-3.12](https://img.shields.io/badge/python-3.9%20|%203.10%20|%203.11|%203.12-blue.svg)](.github/workflows/test.yml)
+[![python-3.9-3.10-3.11-3.12-3.13](https://img.shields.io/badge/python-3.9%20|%203.10%20|%203.11|%203.12|%203.13-blue.svg)](.github/workflows/test.yml)
 
 Add [logfmt](https://www.brandur.org/logfmt) structured logging using the stdlib logging module and without changing a single log call.
 
diff --git a/flake.nix b/flake.nix
index 20b20f5..a0da6be 100644
--- a/flake.nix
+++ b/flake.nix
@@ -18,6 +18,7 @@
             pkgs.python310
             pkgs.python311
             pkgs.python312
+            pkgs.python313
           ];
           shellHook = "unset PYTHONPATH";
         };
diff --git a/runtimes.txt b/runtimes.txt
index 84c4c7c..3e8f011 100644
--- a/runtimes.txt
+++ b/runtimes.txt
@@ -1 +1 @@
-3.9 3.10 3.11 3.12
+3.9 3.10 3.11 3.12 3.13
diff --git a/tox.ini b/tox.ini
index a27b79c..29f58d4 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,5 +1,5 @@
 [tox]
-envlist = py39,py310,py311,py312
+envlist = py39,py310,py311,py312,py313
 
 [testenv]
 deps = pytest