diff --git a/.travis.yml b/.travis.yml
index 367a56280..08ca870a5 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -5,9 +5,11 @@ env:
 - TOXENV=precise
 - TOXENV=trunk
 - TOXENV=pypy
+- TOXENV=py33
 matrix:
   allow_failures:
   - env: TOXENV=pypy
+  - env: TOXENV=py33
 install:
 - ./.travis-workarounds.sh
 - pip install tox
diff --git a/pytest.ini b/pytest.ini
new file mode 100644
index 000000000..8d3bc91a5
--- /dev/null
+++ b/pytest.ini
@@ -0,0 +1,5 @@
+
+[pytest]
+usefixtures = chdir setlog
+python_files=test_*.py __init__.py
+addopts = --doctest-modules
diff --git a/scrapy/conftest.py b/scrapy/conftest.py
new file mode 100644
index 000000000..7e11f331f
--- /dev/null
+++ b/scrapy/conftest.py
@@ -0,0 +1,45 @@
+
+import pytest
+from twisted.python import log
+
+from scrapy import optional_features
+
+collect_ignore = ["stats.py"]
+if 'django' not in optional_features:
+    collect_ignore.append("tests/test_djangoitem/models.py")
+
+
+class LogObservers:
+    """Class for keeping track of log observers across test modules"""
+
+    def __init__(self):
+        self.observers = []
+
+    def add(self, logfile='test.log'):
+        fileobj = open(logfile, 'wb')
+        observer = log.FileLogObserver(fileobj)
+        log.startLoggingWithObserver(observer.emit, 0)
+        self.observers.append((fileobj, observer))
+
+    def remove(self):
+        fileobj, observer = self.observers.pop()
+        log.removeObserver(observer.emit)
+        fileobj.close()
+
+
+@pytest.fixture(scope='module')
+def log_observers():
+    return LogObservers()
+
+
+@pytest.fixture()
+def setlog(request, log_observers):
+    """Attach test.log file observer to twisted log, for trial compatibility"""
+    log_observers.add()
+    request.addfinalizer(log_observers.remove)
+
+
+@pytest.fixture()
+def chdir(tmpdir):
+    """Change to pytest-provided temporary directory"""
+    tmpdir.chdir()
diff --git a/scrapy/contrib/httpcache.py b/scrapy/contrib/httpcache.py
index 5dee898f0..fefebc41c 100644
--- a/scrapy/contrib/httpcache.py
+++ b/scrapy/contrib/httpcache.py
@@ -290,10 +290,11 @@ def parse_cachecontrol(header):
 
     http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.9
 
-    >>> parse_cachecontrol('public, max-age=3600')
-    {'public': None, 'max-age': '3600'}
-    >>> parse_cachecontrol('')
-    {}
+    >>> parse_cachecontrol('public, max-age=3600') == {'public': None,
+    ...                                                'max-age': '3600'}
+    True
+    >>> parse_cachecontrol('') == {}
+    True
 
     """
     directives = {}
diff --git a/scrapy/tests/test_spidermanager/__init__.py b/scrapy/tests/test_spidermanager/__init__.py
index c8697d3b5..eebd6b298 100644
--- a/scrapy/tests/test_spidermanager/__init__.py
+++ b/scrapy/tests/test_spidermanager/__init__.py
@@ -27,6 +27,7 @@ class SpiderManagerTest(unittest.TestCase):
 
     def tearDown(self):
         del self.spiderman
+        del sys.modules['test_spiders_xxx']
         sys.path.remove(self.tmpdir)
 
     def test_interface(self):
diff --git a/scrapy/tests/test_squeue.py b/scrapy/tests/test_squeue.py
index a3c64db8d..83ffcc4b7 100644
--- a/scrapy/tests/test_squeue.py
+++ b/scrapy/tests/test_squeue.py
@@ -7,12 +7,12 @@ from scrapy.contrib.loader import ItemLoader
 class TestItem(Item):
     name = Field()
 
-def test_processor(x):
+def _test_procesor(x):
     return x + x
 
 class TestLoader(ItemLoader):
     default_item_class = TestItem
-    name_out = staticmethod(test_processor)
+    name_out = staticmethod(_test_procesor)
 
 class MarshalFifoDiskQueueTest(t.FifoDiskQueueTest):
 
diff --git a/tests-requirements.txt b/tests-requirements.txt
index 34275dfa7..b7d6a0a56 100644
--- a/tests-requirements.txt
+++ b/tests-requirements.txt
@@ -1,3 +1,4 @@
 # Tests requirements
 mock
 mitmproxy >= 0.10
+pytest-twisted
diff --git a/tox.ini b/tox.ini
index cebffbccc..597abfb5d 100644
--- a/tox.ini
+++ b/tox.ini
@@ -5,6 +5,8 @@
 
 [tox]
 envlist = py27, pypy, precise, trunk, py33
+indexserver =
+    HPK = https://devpi.net/hpk/dev/
 
 [testenv]
 deps =
@@ -15,7 +17,7 @@ deps =
     django
     -rtests-requirements.txt
 commands =
-    trial {posargs:scrapy}
+    py.test --twisted {posargs:scrapy}
 
 [testenv:precise]
 basepython = python2.7
@@ -34,7 +36,7 @@ basepython = python2.7
 commands =
     pip install https://github.com/scrapy/w3lib/archive/master.zip#egg=w3lib
     pip install https://github.com/scrapy/queuelib/archive/master.zip#egg=queuelib
-    trial {posargs:scrapy}
+    py.test --twisted {posargs:scrapy}
 
 [testenv:py33]
 basepython = python3.3
@@ -45,8 +47,10 @@ deps =
     cssselect>=0.9
     queuelib>=1.1.1
     w3lib>=1.5
-commands =
-    trial {posargs:scrapy}
+    # tests requirements
+    mock
+    :HPK:pytest>2.5.2
+    pytest-twisted
 
 [testenv:windows]
 commands =