diff --git a/tox.ini b/tox.ini
index 409ed317c1..9751876e76 100644
--- a/tox.ini
+++ b/tox.ini
@@ -16,7 +16,7 @@ setenv = VIRTUAL_ENV={envdir}
          OS_STDERR_CAPTURE={env:OS_STDERR_CAPTURE:true}
          PYTHONUNBUFFERED=1
 deps =
-  -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
+  -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/2025.2}
   -r{toxinidir}/requirements.txt
   -r{toxinidir}/test-requirements.txt
 commands =
@@ -85,7 +85,7 @@ commands = oslo_debug_helper -t ironic/tests/unit {posargs}
 allowlist_externals = dot
 # NOTE(dtantsur): documentation building process requires importing ironic
 deps =
-  -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
+  -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/2025.2}
   -r{toxinidir}/requirements.txt
   -r{toxinidir}/doc/requirements.txt
 commands = sphinx-build -E -b html doc/source doc/build/html
@@ -103,7 +103,7 @@ commands =
 # NOTE(Mahnoor): documentation building process requires importing ironic API modules
 usedevelop = False
 deps =
-  -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
+  -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/2025.2}
   -r{toxinidir}/requirements.txt
   -r{toxinidir}/doc/requirements.txt
 allowlist_externals = bash
@@ -114,7 +114,7 @@ commands =
 [testenv:releasenotes]
 usedevelop = False
 deps =
-  -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
+  -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/2025.2}
   -r{toxinidir}/doc/requirements.txt
 commands =
   sphinx-build -a -E -W -d releasenotes/build/doctrees -b html releasenotes/source releasenotes/build/html
@@ -126,7 +126,7 @@ setenv = PYTHONHASHSEED=0
 #   environment.
 allowlist_externals = *
 deps =
-  -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
+  -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/2025.2}
   -r{toxinidir}/test-requirements.txt
   -r{toxinidir}/doc/requirements.txt
 commands = {posargs}
@@ -140,7 +140,7 @@ setenv = VIRTUAL_ENV={envdir}
          PYTHONUNBUFFERED=1
          SQLALCHEMY_WARN_20=true
 deps =
-  -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
+  -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/2025.2}
   -r{toxinidir}/requirements.txt
   -r{toxinidir}/driver-requirements.txt
   python-ironicclient