diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 951bc77..8147573 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -20,7 +20,7 @@ jobs:
         tox_env: ${{ matrix.tox_env }}
     strategy:
       matrix:
-        tox_env: [py27, py36, py37, py38, py39, pypy2, pypy3]
+        tox_env: [py27, py36, py38, py39, py310, py311, py312, py313, py314, pypy2, pypy3]
 
     # Use GitHub's Linux Docker host
     runs-on: ubuntu-latest
diff --git a/README.md b/README.md
index 0b14629..d7e64ce 100644
--- a/README.md
+++ b/README.md
@@ -13,8 +13,8 @@ This GitHub action tests a checked-out Python project using
 - uses: fedora-python/tox-github-action
   with:
     # The tox environment to run
-    # Default: py311 (subject to change as new Python releases come out)
-    tox_env: py311
+    # Default: py312 (subject to change as new Python releases come out)
+    tox_env: py312
 ```
 
 Add the action to your workflow file, e.g. `.github/workflows/main.yml`,
@@ -62,6 +62,12 @@ Until version 0.4, this action always used the latest [fedora-python-tox](https:
 image. Since version 34.0, the first number in the version (also sometimes
 referred to as the "major version") represents the release of Fedora used in the image.
 
+### v40.0
+
+* Uses Fedora 40 as the base container image.
+* Python 3.7 is no longer available.
+* Python 3.12 is now the default tox environment if none is configured.
+
 ### v39.0
 
 * Uses Fedora 39 as the base container image.
diff --git a/action.yaml b/action.yaml
index 1ae0f5a..1290a74 100644
--- a/action.yaml
+++ b/action.yaml
@@ -3,7 +3,7 @@ description: Runs tests with Tox
 inputs:
   tox_env:
     required: true
-    default: 'py311'
+    default: 'py312'
     description: Tox environment to run the tests on
   dnf_install:
     required: false
@@ -16,7 +16,7 @@ inputs:
 
 runs:
   using: docker
-  image: docker://fedorapython/fedora-python-tox:f39
+  image: docker://fedorapython/fedora-python-tox:f40
   env:
     TOXENV: ${{ inputs.tox_env }}
     DNF_INSTALL: ${{ inputs.dnf_install }}
diff --git a/pyproject.toml b/pyproject.toml
index 7b4134d..06c64f9 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -5,10 +5,10 @@ build-backend = "setuptools.build_meta"
 [tool.tox]
 legacy_tox_ini = """
 [tox]
-envlist = py27,py36,py37,py38,py39,pypy2,pypy3
+envlist = py27,py36,py38,py39,py310,py311,py312,py313,py314,pypy2,pypy3
 skipsdist = True
 
 [testenv]
-deps = pytest >= 3.0.0, <4
+deps = pytest >= 3.0.0
 commands = pytest test/test.py
 """