diff --git a/tox.ini b/tox.ini
index f532ed9..15d233d 100644
--- a/tox.ini
+++ b/tox.ini
@@ -7,7 +7,7 @@ ignore_basepython_conflict=true
 usedevelop = True
 install_command = pip install -U {opts} {packages}
 deps =
-    -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
+    -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/zed}
     -r{toxinidir}/requirements.txt
     -r{toxinidir}/test-requirements.txt
 basepython = python3
@@ -26,7 +26,7 @@ commands =
 
 [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/zed}
   -r{toxinidir}/doc/requirements.txt
 commands =
   sphinx-build -b html doc/source doc/build/html