diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 37abc0a..f7dbaf6 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -34,7 +34,7 @@ defaults:
 
 env:
   # The default values in the job generated by the matrix.
-  DEFAULT_PYTHON_VERSION: '3.11'
+  DEFAULT_PYTHON_VERSION: '3.13'
 
 jobs:
   testing:
@@ -44,7 +44,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ['3.8', '3.9', '3.10', '3.11', '3.12']
+        python-version: ['3.10', '3.11', '3.12', '3.13', '3.14']
 
     steps:
     - uses: actions/checkout@v3
@@ -67,15 +67,15 @@ jobs:
 
     - name: Test code
       run: |
-        coverage run -m twisted.trial constantly
-        mv .coverage .coverage.${{ matrix.python-version }}
+        coverage run -p -m twisted.trial constantly
 
     - name: Upload coverage data
-      uses: actions/upload-artifact@v3
+      uses: actions/upload-artifact@v7
       with:
         name: coverage-data
         path: .coverage.*
         if-no-files-found: error # 'warn' or 'ignore' are also available.
+        include-hidden-files: true
 
 
   coverage:
@@ -88,11 +88,11 @@ jobs:
     - uses: actions/setup-python@v4
       with:
         # Use latest Python, so it understands all syntax.
-        python-version: 3.11
+        python-version: 3.14
 
     - run: python -Im pip install --upgrade coverage[toml]
 
-    - uses: actions/download-artifact@v3
+    - uses: actions/download-artifact@v8
       with:
         name: coverage-data
 
@@ -134,7 +134,7 @@ jobs:
 
   apidocs:
     name: API docs build
-    runs-on: ubuntu-22.04
+    runs-on: ubuntu-24.04
     steps:
     - uses: actions/checkout@v3
     - name: Set up Python
diff --git a/pyproject.toml b/pyproject.toml
index 9016d4b..dc3d42b 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -10,11 +10,11 @@ classifiers = [
     "Programming Language :: Python",
     "Programming Language :: Python :: 3",
     "Programming Language :: Python :: 3 :: Only",
-    "Programming Language :: Python :: 3.8",
-    "Programming Language :: Python :: 3.9",
     "Programming Language :: Python :: 3.10",
     "Programming Language :: Python :: 3.11",
     "Programming Language :: Python :: 3.12",
+    "Programming Language :: Python :: 3.13",
+    "Programming Language :: Python :: 3.14",
     "Programming Language :: Python :: Implementation :: CPython",
     "Programming Language :: Python :: Implementation :: PyPy",
     "Topic :: Software Development :: Libraries :: Python Modules",
diff --git a/tox.ini b/tox.ini
index 4968f11..7a67d70 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,5 +1,5 @@
 [tox]
-envlist = {py27,pypy,py33,py34}-tests, pyflakes, cov, docs
+envlist = {pypy,py310,py311,py312,py313,py314}-tests, pyflakes, cov, docs
 
 [testenv]
 changedir = {envtmpdir}
@@ -29,7 +29,7 @@ commands = {envbindir}/pyflakes {toxinidir}/constantly
 
 [testenv:docs]
 deps = sphinx
-basepython = python2.7
+basepython = python3.14
 commands =
      {envbindir}/sphinx-build -W -b html {toxinidir}/docs {toxinidir}/docs/_build/html