diff --git a/tox.ini b/tox.ini
index f29bd5dd..d75edfa9 100644
--- a/tox.ini
+++ b/tox.ini
@@ -30,7 +30,7 @@ commands = oslo_debug_helper -t zunclient/tests {posargs}
 
 [testenv:docs]
 deps =
-  -c{env:UPPER_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
+  -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/2025.2}
   -r{toxinidir}/doc/requirements.txt
 commands =
   sphinx-build -W -b html doc/source doc/build/html
@@ -53,7 +53,7 @@ commands =
 
 [testenv:releasenotes]
 deps =
-  -c{env:UPPER_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
+  -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/2025.2}
   -r{toxinidir}/doc/requirements.txt
 commands =
   sphinx-build -a -E -W -d releasenotes/build/doctrees -b html releasenotes/source releasenotes/build/html