diff --git a/conftest.py b/conftest.py
index 76461a45a..9f9a5bca7 100644
--- a/conftest.py
+++ b/conftest.py
@@ -10,7 +10,8 @@ if 'django' not in optional_features:
 
 if six.PY3:
     for fn in open('tests/py3-ignores.txt'):
-        collect_ignore.append(fn.strip())
+        if fn.strip():
+            collect_ignore.append(fn.strip())
 
 class LogObservers:
     """Class for keeping track of log observers across test modules"""
diff --git a/tests/py3-ignores.txt b/tests/py3-ignores.txt
index 685dbc17d..ea69e21de 100644
--- a/tests/py3-ignores.txt
+++ b/tests/py3-ignores.txt
@@ -66,3 +66,34 @@ tests/test_utils_signal.py
 tests/test_utils_template.py
 tests/test_utils_url.py
 tests/test_webclient.py
+
+scrapy/xlib/tx/iweb.py
+scrapy/xlib/tx/interfaces.py
+scrapy/xlib/tx/endpoints.py
+scrapy/xlib/tx/client.py
+scrapy/xlib/tx/_newclient.py
+scrapy/xlib/tx/__init__.py
+scrapy/xlib/tx/__init__.py
+scrapy/utils/testsite.py
+scrapy/http/cookies.py
+scrapy/core/downloader/handlers/s3.py
+scrapy/core/downloader/handlers/http11.py
+scrapy/core/downloader/handlers/http.py
+scrapy/core/downloader/handlers/ftp.py
+scrapy/core/downloader/webclient.py
+scrapy/contrib/pipeline/images.py
+scrapy/contrib/pipeline/files.py
+scrapy/contrib/linkextractors/sgml.py
+scrapy/contrib/linkextractors/regex.py
+scrapy/contrib/linkextractors/htmlparser.py
+scrapy/contrib/downloadermiddleware/retry.py
+scrapy/contrib/downloadermiddleware/httpproxy.py
+scrapy/contrib/downloadermiddleware/cookies.py
+scrapy/contrib/downloadermiddleware/ajaxcrawl.py
+scrapy/contrib/statsmailer.py
+scrapy/contrib/memusage.py
+scrapy/contrib/feedexport.py
+scrapy/commands/deploy.py
+scrapy/commands/bench.py
+scrapy/telnet.py
+scrapy/mail.py
diff --git a/tox.ini b/tox.ini
index 5e57a6ed6..20d54b658 100644
--- a/tox.ini
+++ b/tox.ini
@@ -47,18 +47,15 @@ deps =
     cssselect>=0.9
     queuelib>=1.1.1
     w3lib>=1.5
+    Pillow
     # tests requirements
     mock
     pytest>=2.6.0
     pytest-twisted
-commands =
-    py.test {posargs:tests}
 
 [testenv:py34]
 basepython = python3.4
 deps = {[testenv:py33]deps}
-commands =
-    py.test {posargs:tests}
 
 [testenv:docs]
 changedir = docs