diff --git a/tox.ini b/tox.ini
index 9642338..134cf66 100644
--- a/tox.ini
+++ b/tox.ini
@@ -8,7 +8,7 @@ ignore_basepython_conflict = True
 basepython = python3
 usedevelop = True
 install_command =
-    pip install -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master} {opts} {packages}
+    pip install -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/wallaby} {opts} {packages}
 commands =
     /usr/bin/find . -type f -name "*.pyc" -delete
 passenv =