diff --git a/.travis.yml b/.travis.yml
index 5727e094..a694dc70 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -4,7 +4,6 @@ python:
   - "3.6"
   - "3.5"
   - "3.4"
-  - "3.3"
   - "2.7"
 
 sudo: false
diff --git a/README.rst b/README.rst
index 8c151328..fc7e21c6 100644
--- a/README.rst
+++ b/README.rst
@@ -90,7 +90,7 @@ More documentation is available at https://html5lib.readthedocs.io/.
 Installation
 ------------
 
-html5lib works on CPython 2.7+, CPython 3.3+ and PyPy.  To install it,
+html5lib works on CPython 2.7+, CPython 3.4+ and PyPy.  To install it,
 use:
 
 .. code-block:: bash
diff --git a/setup.py b/setup.py
index 3e413f2a..ce85d497 100644
--- a/setup.py
+++ b/setup.py
@@ -66,7 +66,6 @@ def default_environment():
     'Programming Language :: Python :: 2',
     'Programming Language :: Python :: 2.7',
     'Programming Language :: Python :: 3',
-    'Programming Language :: Python :: 3.3',
     'Programming Language :: Python :: 3.4',
     'Programming Language :: Python :: 3.5',
     'Programming Language :: Python :: 3.6',
diff --git a/tox.ini b/tox.ini
index e07ef670..8e4a0835 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,5 +1,5 @@
 [tox]
-envlist = {py27,py33,py34,py35,py36,pypy}-{base,six19,optional}
+envlist = {py27,py34,py35,py36,pypy}-{base,six19,optional}
 
 [testenv]
 deps =