diff --git a/tox.ini b/tox.ini
index d10720bbf0..f0cce38ca9 100644
--- a/tox.ini
+++ b/tox.ini
@@ -8,7 +8,7 @@ ignore_basepython_conflict = True
 usedevelop = True
 basepython = python3
 install_command =
-    pip install -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/2023.2} {opts} {packages}
+    pip install -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master} {opts} {packages}
 deps =
     -r{toxinidir}/global-requirement-pins.txt
     -r{toxinidir}/test-requirements.txt