diff --git a/tox.ini b/tox.ini
index 2ae4a8a92..85b3429e3 100644
--- a/tox.ini
+++ b/tox.ini
@@ -18,14 +18,12 @@ commands =
   bash -c 'set -o pipefail ; py.test -n 8 --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 test/pathod/test_language_http2.py 2>&1 | grep -v Cryptography_locking_cb'
 
 [testenv:py27-ci]
-basepython = python2.7
 commands =
   py.test --cov netlib --cov mitmproxy --cov pathod --color=yes --timeout 60 ./test
   codecov -e TOXENV
 
 [testenv:py35-ci]
 # remove bash & pipe & grep hack after cryptography ships with openssl 1.1.0
-basepython = python3.5
 whitelist_externals = bash
 commands =
   bash -c 'set -o pipefail ; 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 test/pathod/test_language_http2.py 2>&1 | grep -v Cryptography_locking_cb'