diff --git a/tox.ini b/tox.ini
index a12bed0ffc..e56cb14fd1 100644
--- a/tox.ini
+++ b/tox.ini
@@ -7,6 +7,7 @@ envlist = functional,pep8
 install_command = pip install -U {opts} {packages}
 deps = -r{toxinidir}/requirements.txt
        -r{toxinidir}/test-requirements.txt
+passenv = http_proxy HTTP_PROXY https_proxy HTTPS_PROXY no_proxy NO_PROXY
 
 [testenv:pep8]
 commands =