diff --git a/tox.ini b/tox.ini
index 233609e01..c437f2759 100644
--- a/tox.ini
+++ b/tox.ini
@@ -18,7 +18,7 @@ passenv =
     no_proxy
     NO_PROXY
 deps =
-  -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
+  -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/2023.2}
   -r{toxinidir}/test-requirements.txt
   -r{toxinidir}/requirements.txt
   # javascript engine
@@ -78,7 +78,7 @@ commands = {posargs}
 #set PYTHONHASHSEED=0 to prevent wsmeext.sphinxext from randomly failing.
 [testenv:docs]
 deps =
-  -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
+  -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/2023.2}
   -r{toxinidir}/doc/requirements.txt
   -r{toxinidir}/requirements.txt
 setenv = PYTHONHASHSEED=0
@@ -88,7 +88,7 @@ commands =
 
 [testenv:pdf-docs]
 deps =
-  -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
+  -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/2023.2}
   -r{toxinidir}/doc/requirements.txt
 allowlist_externals =
   make