diff --git a/.appveyor.yml b/.appveyor.yml
index d53a4f2..c0005b8 100644
--- a/.appveyor.yml
+++ b/.appveyor.yml
@@ -13,8 +13,6 @@ environment:
     # http://www.appveyor.com/docs/installed-software#python
     - PYTHON: "C:\\Python27"
     - PYTHON: "C:\\Python27-x64"
-    - PYTHON: "C:\\Python33"
-    - PYTHON: "C:\\Python33-x64"
       DISTUTILS_USE_SDK: "1"
     - PYTHON: "C:\\Python34"
     - PYTHON: "C:\\Python34-x64"
diff --git a/.travis.yml b/.travis.yml
index 2e2ebc4..7b96ecb 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -21,4 +21,5 @@ after_success:
   - codecov
 matrix:
   allow_failures:
+    - python: "3.3"
     - python: "nightly"
diff --git a/README.md b/README.md
index 3408628..11538e4 100644
--- a/README.md
+++ b/README.md
@@ -66,8 +66,7 @@ a bug in pynacl which gets confused when the libsodium runtime is installed
 (e.g. `libsodium13`) but not the development package.
 
 Developers can clone the source tree and run `tox` to run the unit tests on
-all supported (and installed) versions of python: 2.7, 3.3, 3.4, 3.5, and
-3.6.
+all supported (and installed) versions of python: 2.7, 3.4, 3.5, and 3.6.
 
 ## Motivation
 
@@ -234,8 +233,8 @@ If this happens, run `pip install -e .[dev]` again.
 
 This library is released under the MIT license, see LICENSE for details.
 
-This library is compatible with python2.7, 3.3, 3.4, 3.5, and 3.6 . It
-is probably compatible with py2.6, but the latest Twisted (>=15.5.0) is
+This library is compatible with python2.7, 3.4, 3.5, and 3.6 . It is
+probably compatible with py2.6, but the latest Twisted (>=15.5.0) is
 not.
 
 
diff --git a/tox.ini b/tox.ini
index 114911c..1943025 100644
--- a/tox.ini
+++ b/tox.ini
@@ -4,7 +4,7 @@
 # and then run "tox" from this directory.
 
 [tox]
-envlist = {py27,py33,py34,py35,py36,pypy}
+envlist = {py27,py34,py35,py36,pypy}
 skip_missing_interpreters = True
 minversion = 2.4.0