diff --git a/.travis.yml b/.travis.yml
index dad81c379..b0a4ea10d 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -14,20 +14,21 @@ matrix:
   fast_finish: true
   include:
     - python: 2.7
+      env: TOXENV=py27
     - python: 2.7
-      env: NO_ALPN=1
+      env: TOXENV=py27 NO_ALPN=1
+    - python: 3.5
+      env: TOXENV=py35
+    - python: 3.5
+      env: TOXENV=py35 NO_ALPN=1
     - language: generic
+      env: TOXENV=py27
       os: osx
       osx_image: xcode7.1
       git:
         depth: 9999999
-    - python: 3.5
-      env: SCOPE="netlib test/mitmproxy/script test/pathod/test_utils.py test/pathod/test_log.py test/pathod/test_language_generators.py test/pathod/test_language_writer.py test/pathod/test_language_base.py test/pathod/test_language_http.py test/pathod/test_language_websocket.py"
-    - python: 3.5
-      env: SCOPE="netlib test/mitmproxy/script test/pathod/test_utils.py test/pathod/test_log.py test/pathod/test_language_generators.py test/pathod/test_language_writer.py test/pathod/test_language_base.py test/pathod/test_language_http.py test/pathod/test_language_websocket.py" NO_ALPN=1
     - python: 2.7
-      env: DOCS=1
-      script: 'cd docs && SPHINXOPTS="-W" make -e html'
+      env: TOXENV=docs
   allow_failures:
     - python: pypy
 
@@ -39,23 +40,20 @@ install:
       brew outdated openssl || brew upgrade openssl
       brew install python
     fi
-  - pip install -U virtualenv codecov
-  - ./dev.sh
-  - source venv/bin/activate
 
 before_script:
-  - "openssl version -a"
-  - "python -c \"from OpenSSL import SSL; print(SSL.SSLeay_version(SSL.SSLEAY_VERSION))\""
-  - "flake8 --jobs 4 --count mitmproxy netlib pathod examples test"
+  - "pip install tox"
+  - "tox -e lint"
 
-script:
-  - "py.test --timeout 60 --cov netlib --cov mitmproxy --cov pathod test/$SCOPE"
+script: tox
 
 after_success:
-  - codecov
   - |
     if [[ $TRAVIS_OS_NAME == "osx" && $TRAVIS_PULL_REQUEST == "false" && ($TRAVIS_BRANCH == "master" || -n $TRAVIS_TAG) ]]
     then
+        pip install -U virtualenv
+        ./dev.sh
+        source venv/bin/activate
         pip install -e ./release
         python ./release/rtool.py bdist
         python ./release/rtool.py upload-snapshot --bdist --wheel
@@ -71,7 +69,6 @@ notifications:
 
 cache:
   directories:
-    - $HOME/build/mitmproxy/mitmproxy/venv
+    - $HOME/build/mitmproxy/mitmproxy/.tox
     - $HOME/.cache/pip
     - $HOME/.pyenv
-    - $HOME/Library/Caches/pip
diff --git a/setup.py b/setup.py
index e8829d492..050043b36 100644
--- a/setup.py
+++ b/setup.py
@@ -97,8 +97,8 @@ setup(
             "ipaddress>=1.0.15, <1.1",
         ],
         'dev': [
+            "tox>=2.3, <3",
             "mock>=2.0, <2.1",
-            "flake8>=2.5.4, <3",
             "pytest>=2.8.7, <2.10",
             "pytest-cov>=2.2.1, <2.3",
             "pytest-timeout>=1.0.0, <1.1",
diff --git a/tox.ini b/tox.ini
index 9fb563a0d..b75f536ff 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,15 +1,31 @@
 [tox]
-envlist = py27, py35, lint
+envlist = py27, py35, docs, lint
 
 [testenv]
-deps = -rrequirements.txt
+deps =
+  -rrequirements.txt
+  codecov>=2.0.5
+passenv = CI TRAVIS_BUILD_ID TRAVIS TRAVIS_BRANCH TRAVIS_JOB_NUMBER TRAVIS_PULL_REQUEST TRAVIS_JOB_ID TRAVIS_REPO_SLUG TRAVIS_COMMIT
 
 [testenv:py27]
-commands = py.test -n 8 --timeout 60 ./test
+commands =
+  py.test --cov netlib --cov mitmproxy --cov pathod --color=yes --timeout 60 ./test
+  codecov -e TOXENV
 
 [testenv:py35]
-commands = py.test -n 8 --timeout 60 test/netlib test/mitmproxy/script test/pathod/test_utils.py test/pathod/test_log.py test/pathod/test_language_generators.py test/pathod/test_language_writer.py test/pathod/test_language_base.py test/pathod/test_language_http.py test_language_websocket.py
+# remove bash & pipe & grep hack after cryptography ships with openssl 1.1.0
+whitelist_externals = bash
+commands =
+  bash -c 'py.test --cov netlib --cov mitmproxy --cov pathod --color=yes --timeout 60 test/netlib test/mitmproxy/script test/pathod/test_utils.py test/pathod/test_log.py test/pathod/test_language_generators.py test/pathod/test_language_writer.py test/pathod/test_language_base.py test/pathod/test_language_http.py test/pathod/test_language_websocket.py 2>&1 | grep -v Cryptography_locking_cb'
+  codecov -e TOXENV
+
+[testenv:docs]
+basepython = python2.7
+whitelist_externals = make
+changedir = docs
+setenv = SPHINXOPTS="-W"
+commands = make -e html
 
 [testenv:lint]
-deps = flake8
-commands = flake8 --count mitmproxy netlib pathod examples test
+deps = flake8>=2.5.4, <3
+commands = flake8 --jobs 8 --count mitmproxy netlib pathod examples test