diff --git a/tox.ini b/tox.ini
index 0ea8522..012e06b 100644
--- a/tox.ini
+++ b/tox.ini
@@ -11,7 +11,7 @@ passenv = http_proxy
           no_proxy
           NO_PROXY
 usedevelop = True
-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