diff --git a/AUTHORS b/AUTHORS
index 0254dbfdf..c6235fc64 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -40,3 +40,4 @@ Piotr Banaszkiewicz
 Jurko Gospodnetić
 Marc Schlaich
 Christopher Gilling
+Daniel Grana
diff --git a/CHANGELOG b/CHANGELOG
index ce1009166..7ebe9e866 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -26,11 +26,12 @@ NEXT (2.6)
 - fix issue412: messing with stdout/stderr FD-level streams is now
   captured without crashes.
 
+- fix issue483: trial/py33 works now properly.  Thanks Daniel Grana for PR.
+
 - simplified internal capturing mechanism and made it more robust
   against tests or setups changing FD1/FD2, also better integrated
   now with pytest.pdb() in single tests.
 
-
 2.5.2
 -----------------------------------
 
diff --git a/_pytest/unittest.py b/_pytest/unittest.py
index e6fefbd43..12c1cfd53 100644
--- a/_pytest/unittest.py
+++ b/_pytest/unittest.py
@@ -154,7 +154,7 @@ def pytest_runtest_protocol(item, __multicall__):
     if isinstance(item, TestCaseFunction):
         if 'twisted.trial.unittest' in sys.modules:
             ut = sys.modules['twisted.python.failure']
-            Failure__init__ = ut.Failure.__init__.im_func
+            Failure__init__ = ut.Failure.__init__
             check_testcase_implements_trial_reporter()
             def excstore(self, exc_value=None, exc_type=None, exc_tb=None,
                 captureVars=None):
diff --git a/tox.ini b/tox.ini
index d960cd22b..d48ff874f 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
@@ -45,7 +45,7 @@ commands=
 
 [testenv:py33-pexpect]
 changedir=testing
-basepython=python2.7
+basepython=python3.3
 deps={[testenv:py27-pexpect]deps}
 commands=
   py.test -rfsxX test_pdb.py test_terminal.py test_unittest.py
@@ -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