diff --git a/tox.ini b/tox.ini
index 57ce54a..565a1db 100644
--- a/tox.ini
+++ b/tox.ini
@@ -7,7 +7,7 @@ deps =
   -c{env:UPPER_CONSTRAINTS_FILE:https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt}
   -r{toxinidir}/test-requirements.txt
   -r{toxinidir}/requirements.txt
-install_command = pip install -U {opts} {packages}
+install_command = pip install {opts} {packages}
 commands = python setup.py testr --slowest --testr-args='{posargs}'
 
 [testenv:pep8]