diff --git a/tox.ini b/tox.ini
index 915740f..29dddd4 100644
--- a/tox.ini
+++ b/tox.ini
@@ -9,7 +9,7 @@ setenv = VIRTUAL_ENV={envdir}
          OS_STDOUT_NOCAPTURE=False
          OS_STDERR_NOCAPTURE=False
 deps =
-    -c{env:UPPER_CONSTRAINTS_FILE:https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt}
+    -c{env:TOX_CONSTRAINTS_FILE:https://raw.githubusercontent.com/sapcc/requirements/stable/2025.2-m3/upper-constraints.txt}
     -r{toxinidir}/requirements.txt
     -r{toxinidir}/test-requirements.txt
 commands = stestr run {posargs}