diff --git a/tox.ini b/tox.ini
index a41bd616b..e223af0e7 100644
--- a/tox.ini
+++ b/tox.ini
@@ -12,6 +12,7 @@ setenv =
 deps = -r{toxinidir}/requirements.txt
        -r{toxinidir}/test-requirements.txt
 commands = python setup.py test --slowest --testr-args='{posargs}'
+passenv = http_proxy HTTP_PROXY https_proxy HTTPS_PROXY no_proxy NO_PROXY
 
 [testenv:pep8]
 basepython = python3