diff --git a/tox.ini b/tox.ini
index e2851d42..3da5cb83 100644
--- a/tox.ini
+++ b/tox.ini
@@ -16,7 +16,7 @@ passenv = http_proxy
 whitelist_externals = bash
                       find
                       rm
-install_command = pip install -U {opts} {packages}
+install_command = pip install {opts} {packages}
 deps =
        -c{env:UPPER_CONSTRAINTS_FILE:https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt}
        -r{toxinidir}/requirements.txt