diff --git a/tox.ini b/tox.ini
index d960cd22b..7ef07329e 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,6 +1,6 @@
 [tox]
 distshare={homedir}/.tox/distshare
-envlist=flakes,py26,py27,pypy,py27-pexpect,py33-pexpect,py27-nobyte,py32,py33,py27-xdist,py33-xdist,trial
+envlist=flakes,py26,py27,pypy,py27-pexpect,py33-pexpect,py27-nobyte,py32,py33,py27-xdist,py33-xdist,py27-trial,py33-trial
 
 [testenv]
 changedir=testing
@@ -61,12 +61,22 @@ commands=
   py.test -n3 -rfsxX \
         --junitxml={envlogdir}/junit-{envname}.xml {posargs:testing}
 
-[testenv:trial]
+[testenv:py27-trial]
 changedir=.
+basepython=python2.7
 deps=twisted
 commands=
   py.test -rsxf \
         --junitxml={envlogdir}/junit-{envname}.xml {posargs:testing/test_unittest.py}
+
+[testenv:py33-trial]
+changedir=.
+basepython=python3.3
+deps={[testenv:py27-trial]deps}
+commands=
+  py.test -rsxf \
+        --junitxml={envlogdir}/junit-{envname}.xml {posargs:testing/test_unittest.py}
+
 [testenv:doctest]
 changedir=.
 commands=py.test --doctest-modules _pytest