diff --git a/tox.ini b/tox.ini
index 7792f5114b..b1b1fad4ce 100644
--- a/tox.ini
+++ b/tox.ini
@@ -4,9 +4,10 @@ envlist = py39,pep8,api-ref,docs,genconfig,genpolicy,releasenotes,protection
 ignore_basepython_conflict = true
 
 [testenv]
-usedevelop = True
 basepython = python3
-setenv = VIRTUAL_ENV={envdir}
+usedevelop = True
+setenv =
+  PYTHONDONTWRITEBYTECODE=1
 deps =
   -c{env:UPPER_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
   -r{toxinidir}/test-requirements.txt