diff --git a/tox.ini b/tox.ini
index 7b3d951d20..380f64fdc4 100644
--- a/tox.ini
+++ b/tox.ini
@@ -11,7 +11,7 @@ setenv =
     OS_STDERR_CAPTURE=1
     OS_TEST_TIMEOUT=60
 deps =
-    -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
+    -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/2025.1}
     -r{toxinidir}/test-requirements.txt
     -r{toxinidir}/requirements.txt
 commands =
@@ -63,7 +63,7 @@ commands =
 description =
     Run specified command in a virtual environment with all dependencies installed.
 deps =
-    -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
+    -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/2025.1}
     -r{toxinidir}/requirements.txt
     -r{toxinidir}/doc/requirements.txt
 commands =
@@ -93,7 +93,7 @@ commands =
 description =
     Build documentation in HTML format.
 deps =
-    -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
+    -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/2025.1}
     -r{toxinidir}/doc/requirements.txt
 commands =
     sphinx-build -a -E -W -d doc/build/doctrees -b html doc/source doc/build/html
@@ -105,7 +105,7 @@ commands =
 description =
     Build release note documentation in HTML format.
 deps =
-    -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
+    -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/2025.1}
     -r{toxinidir}/doc/requirements.txt
 commands =
     sphinx-build -a -E -W -d releasenotes/build/doctrees -b html releasenotes/source releasenotes/build/html