diff --git a/README.md b/README.md
index 24d4e8b..cffcb8a 100644
--- a/README.md
+++ b/README.md
@@ -18,7 +18,7 @@ to do is delete your existing cassette files, and run your tests again.
 All of the mocked responses will be updated with the new API.
 
 ## Compatibility Notes
-VCR.py supports Python 2.6 and 2.7, 3.4, and [pypy](http://pypy.org).
+VCR.py supports Python 2.6 and 2.7, 3.3, 3.4, and [pypy](http://pypy.org).
 
 The following http libraries are supported:
 
diff --git a/tox.ini b/tox.ini
index 40965a2..3ab6669 100644
--- a/tox.ini
+++ b/tox.ini
@@ -7,6 +7,7 @@
 envlist = 
     py26
     py27
+    py33
     py34
     pypy
     py26requests
@@ -15,10 +16,12 @@ envlist =
     pypyrequests
     py26oldrequests
     py27oldrequests
+    py33oldrequests
     py34oldrequests
     pypyoldrequests
     py26httplib2
     py27httplib2
+    py33httplib2
     py34httplib2
     pypyhttplib2
 
@@ -46,6 +49,14 @@ deps =
     PyYAML
     requests==1.2.3
 
+[testenv:py33oldrequests]
+basepython = python3.3
+deps =
+    mock
+    pytest
+    PyYAML
+    requests==1.2.3
+
 [testenv:py34oldrequests]
 basepython = python3.4
 deps =
@@ -78,6 +89,14 @@ deps =
     PyYAML
     requests
 
+[testenv:py33requests]
+basepython = python3.4
+deps =
+    mock
+    pytest
+    PyYAML
+    requests
+
 [testenv:py34requests]
 basepython = python3.4
 deps =
@@ -110,6 +129,14 @@ deps =
     PyYAML
     httplib2
 
+[testenv:py33httplib2]
+basepython = python3.4
+deps =
+    mock
+    pytest
+    PyYAML
+    httplib2
+
 [testenv:py34httplib2]
 basepython = python3.4
 deps =