diff --git a/tox.ini b/tox.ini
index b3c4106a..52b315b1 100644
--- a/tox.ini
+++ b/tox.ini
@@ -2,6 +2,11 @@
 envlist = pep8,docs,py27,py3{4,5,6,7}
 
 [testenv]
+# See "testing behind a proxy"
+# @ https://review.openstack.org/#/q/I764ed51314c8e2d0572d1f0
+passenv = http_proxy https_proxy
+# passenv = http_proxy https_proxy _JAVA_OPTIONS
+
 commands =
   python -m git_review.tests.check_test_id_hashes discover --list
   python -m git_review.tests.prepare