diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 1419d6ba..de37764e 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -8,7 +8,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ["3.9", "3.10", "3.11", "3.12", "pypy3.9", "pypy3.10"]
+        python-version: ["3.10", "3.11", "3.12", "3.13", "3.14", "pypy3.10"]
 
     steps:
       - uses: actions/checkout@v5
diff --git a/NEWS b/NEWS
index 40b5866b..40b11b5b 100644
--- a/NEWS
+++ b/NEWS
@@ -3,6 +3,16 @@ testtools NEWS
 
 Changes and improvements to testtools_, grouped by release.
 
+NEXT
+~~~~
+
+Changes
+-------
+
+* Drop support for Python 3.9. (Jelmer Vernooij)
+
+* Add support for Python 3.13 and 3.14. (Jelmer Vernooij)
+
 2.8.0
 ~~~~~
 
diff --git a/README.rst b/README.rst
index 0f77f88f..2895048a 100644
--- a/README.rst
+++ b/README.rst
@@ -34,7 +34,7 @@ under the same license as Python, see LICENSE for details.
 Supported platforms
 -------------------
 
-* Python 3.9+ or PyPy3
+* Python 3.10+ or PyPy3
 
 If you would like to use testtools for earlier Pythons, consult the compatibility docs:
 
diff --git a/doc/overview.rst b/doc/overview.rst
index f21c53af..c02d1bc1 100644
--- a/doc/overview.rst
+++ b/doc/overview.rst
@@ -84,7 +84,7 @@ Cross-Python compatibility
 --------------------------
 
 testtools gives you the very latest in unit testing technology in a way that
-will work with Python 3.9+ and PyPy3.
+will work with Python 3.10+ and PyPy3.
 
 If you wish to use testtools with Python 2.4 or 2.5, then please use testtools
 0.9.15.
diff --git a/pyproject.toml b/pyproject.toml
index 983a885b..3290db04 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -14,10 +14,11 @@ classifiers = [
     "Operating System :: OS Independent",
     "Programming Language :: Python",
     "Programming Language :: Python :: 3",
-    "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 :: 3 :: Only",
     "Programming Language :: Python :: Implementation :: CPython",
     "Programming Language :: Python :: Implementation :: PyPy",
@@ -26,7 +27,7 @@ classifiers = [
     "Topic :: Software Development :: Testing",
 ]
 dynamic = ["version"]
-requires-python = ">=3.9"
+requires-python = ">=3.10"
 
 [project.urls]
 Homepage = "https://github.com/testing-cabal/testtools"
diff --git a/testtools/testresult/real.py b/testtools/testresult/real.py
index 626f1240..9e430b70 100644
--- a/testtools/testresult/real.py
+++ b/testtools/testresult/real.py
@@ -221,7 +221,6 @@ def startTestRun(self):
         self.unexpectedSuccesses = []
         self.failfast = failfast
         # -- End:   As per python 2.7 --
-        # -- Python 3.5
         self.tb_locals = tb_locals
         # -- Python 3.12
         self.collectedDurations = []
diff --git a/testtools/tests/test_testresult.py b/testtools/tests/test_testresult.py
index 366d7ef6..3c60cc7a 100644
--- a/testtools/tests/test_testresult.py
+++ b/testtools/tests/test_testresult.py
@@ -3053,11 +3053,9 @@ def test_syntax_error(self):
         """Syntax errors should still have fancy special-case formatting"""
         if platform.python_implementation() == "PyPy":
             spaces = "         "
-        elif sys.version_info >= (3, 10):
-            spaces = "        "
         else:
-            spaces = "          "
-        marker = "^^^" if sys.version_info >= (3, 10) else "^"
+            spaces = "        "
+        marker = "^^^"
         textoutput = self._test_external_case("exec ('f(a, b c)')")
         self.assertIn(
             self._as_output(
@@ -3143,7 +3141,7 @@ def test_syntax_error_line_utf_8(self):
         textoutput = self._setup_external_case("import bad")
         self._write_module("bad", "utf-8", f"\ufeff^ = 0 # {text}\n")
         textoutput = self._run_external_case()
-        # Python 3.9 no longer prints the '\ufeff'
+        # Python no longer prints the '\ufeff'
         textoutput = textoutput.replace("\ufeff", "")
         self.assertThat(
             textoutput,
diff --git a/testtools/twistedsupport/_spinner.py b/testtools/twistedsupport/_spinner.py
index e0904204..b26d1d83 100644
--- a/testtools/twistedsupport/_spinner.py
+++ b/testtools/twistedsupport/_spinner.py
@@ -17,7 +17,7 @@
 ]
 
 import signal
-from typing import ClassVar, Union
+from typing import ClassVar
 
 from fixtures import Fixture
 from twisted.internet import defer
@@ -159,7 +159,7 @@ class Spinner:
     # the ideal, and it actually works for many cases.
     _OBLIGATORY_REACTOR_ITERATIONS = 0
 
-    _failure: Union[Failure, object]
+    _failure: Failure | object
 
     def __init__(self, reactor, debug=False):
         """Construct a Spinner.
diff --git a/tox.ini b/tox.ini
index 02edefaf..545fccfb 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,5 +1,5 @@
 [tox]
-envlist = py39,py310,py311,py312,py313,pypy3
+envlist = py310,py311,py312,py313,py314,pypy3
 minversion = 4.2
 
 [testenv]