diff --git a/tox.ini b/tox.ini
index fc5fbbf38ff..83c12ca3690 100644
--- a/tox.ini
+++ b/tox.ini
@@ -7,7 +7,9 @@ skipsdist = True
 setenv = VIRTUAL_ENV={envdir}
 passenv = TRACE_FAILONLY
 usedevelop = True
-install_command = pip install -U {opts} {packages}
+install_command =
+                  constraints: pip install -U -c{env:UPPER_CONSTRAINTS_FILE:https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt} {opts} {packages}
+                  pip install -U {opts} {packages}
 deps = -r{toxinidir}/requirements.txt
        -r{toxinidir}/test-requirements.txt
 whitelist_externals = sh