diff --git a/tox.ini b/tox.ini
index 03ea01d..9933b48 100644
--- a/tox.ini
+++ b/tox.ini
@@ -35,3 +35,11 @@ commands = python setup.py testr --coverage --testr-args='{posargs}'
 show-source = True
 ignore = E123,E125,H803
 exclude=.venv,.git,.tox,dist,doc,*openstack/common*,*lib/python*,*egg,build
+
+[testenv:pip-missing-reqs]
+# do not install test-requirements as that will pollute the virtualenv for
+# determining missing packages
+# this also means that pip-missing-reqs must be installed separately, outside
+# of the requirements.txt files
+deps = pip_missing_reqs
+commands = pip-missing-reqs -d --ignore-module=oslo_serialization* --ignore-module=pkg_resources --ignore-file=oslo_serialization/test.py --ignore-file=oslo_serialization/tests/* oslo_serialization
\ No newline at end of file