diff --git a/python/tox.ini b/python/tox.ini
index 74b2ac05bf..a05460b5c4 100644
--- a/python/tox.ini
+++ b/python/tox.ini
@@ -4,6 +4,7 @@ envlist =
 
 [testenv]
 usedevelop=true
+passenv = CC
 setenv =
     cpp: LD_LIBRARY_PATH={toxinidir}/../src/.libs
     cpp: DYLD_LIBRARY_PATH={toxinidir}/../src/.libs