diff --git a/README.rst b/README.rst
index 561e61a..a8afa71 100644
--- a/README.rst
+++ b/README.rst
@@ -28,7 +28,7 @@ enterprise applications, or web servers ... let imagination run wild.
 Dependencies to build/selftest
 ==============================
 
-* Python 2.6+ (or 3.3+)
+* Python 3.9+
 * docutils
 * testtools (http://pypi.python.org/pypi/testtools/)
 * fixtures (http://pypi.python.org/pypi/fixtures)
@@ -36,7 +36,7 @@ Dependencies to build/selftest
 Dependencies to use testresources
 =================================
 
-* Python 2.6+ (or 3.3+)
+* Python 3.9+
 
 For older versions of Python, testresources <= 1.0.0 supported 2.4, 2.5 and
 3.2.
diff --git a/tox.ini b/tox.ini
index f8db950..c6aee83 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,8 +1,9 @@
 [tox]
-envlist = py26,py27,py33,py34
+envlist = py39,py310,py311,py312,py313
 
 [testenv]
 deps = .[test]
+allowlist_externals = rst2html.py
 commands =
     python -m testtools.run discover
-    rst2html.py --strict README /dev/null
+    rst2html.py --strict README.rst /dev/null