diff --git a/tox.ini b/tox.ini
index 0de6f3b834fb..4c4c39e82f7b 100644
--- a/tox.ini
+++ b/tox.ini
@@ -7,16 +7,15 @@ skipsdist = True
 usedevelop = True
 # tox is silly... these need to be separated by a newline....
 whitelist_externals = bash
-                      find
                       rm
 install_command = pip install -c{env:UPPER_CONSTRAINTS_FILE:https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt} {opts} {packages}
 setenv = VIRTUAL_ENV={envdir}
          OS_TEST_PATH=./nova/tests/unit
          LANGUAGE=en_US
          LC_ALL=en_US.utf-8
+         PYTHONDONTWRITEBYTECODE=1
 deps = -r{toxinidir}/test-requirements.txt
 commands =
-  find . -type f -name "*.pyc" -delete
   bash tools/pretty_tox.sh '{posargs}'
 passenv = http_proxy HTTP_PROXY https_proxy HTTPS_PROXY no_proxy NO_PROXY OS_DEBUG
 # there is also secret magic in pretty_tox.sh which lets you run in a fail only
@@ -34,13 +33,11 @@ commands =
 # other way around. See: https://bugs.launchpad.net/testrepository/+bug/1212909
 setenv = {[testenv]setenv}
 commands =
-  find . -type f -name "*.pyc" -delete
   bash tools/pretty_tox3.sh '{posargs}'
 
 [testenv:py35]
 setenv = {[testenv]setenv}
 commands =
-  find . -type f -name "*.pyc" -delete
   bash tools/pretty_tox3.sh '{posargs}'
 
 [testenv:functional]
@@ -49,7 +46,6 @@ setenv = VIRTUAL_ENV={envdir}
        OS_TEST_PATH=./nova/tests/functional
        LANGUAGE=en_US
 commands =
-  find . -type f -name "*.pyc" -delete
   bash tools/pretty_tox.sh '{posargs}'
 
 [testenv:api-samples]
@@ -60,7 +56,6 @@ setenv = VIRTUAL_ENV={envdir}
        OS_TEST_PATH=./nova/tests/functional/api_sample_tests
        LANGUAGE=en_US
 commands =
-  find . -type f -name "*.pyc" -delete
   bash tools/pretty_tox.sh '{posargs}'
 
 [testenv:genconfig]