diff --git a/tox.ini b/tox.ini
index ab467abd0..205fe1531 100644
--- a/tox.ini
+++ b/tox.ini
@@ -50,7 +50,7 @@ commands =
 
 [testenv:py36]
 # git inside of ratchet.sh needs $HOME.
-passenv = HOME
+passenv = HOME LC_ALL
 commands = {toxinidir}/misc/python3/ratchet.sh
 
 [testenv:integration]