diff --git a/.zuul.yaml b/.zuul.yaml
index 4617aa5e3d..b60d9055d3 100644
--- a/.zuul.yaml
+++ b/.zuul.yaml
@@ -718,7 +718,10 @@
             irrelevant-files:
               - ^.*\.rst$
               - ^doc/.*$
+        # TODO(gmann): make it voting once it is fixed, currently it is failing
+        # on stable/xena https://zuul.openstack.org/builds?job_name=openstacksdk-functional-devstack&branch=stable%2Fxena&skip=0
         - openstacksdk-functional-devstack:
+            voting: false
             irrelevant-files:
               - ^.*\.rst$
               - ^doc/.*$
@@ -752,10 +755,10 @@
             irrelevant-files:
               - ^.*\.rst$
               - ^doc/.*$
-        - openstacksdk-functional-devstack:
-            irrelevant-files:
-              - ^.*\.rst$
-              - ^doc/.*$
+        # - openstacksdk-functional-devstack:
+        #    irrelevant-files:
+        #      - ^.*\.rst$
+        #      - ^doc/.*$
         - tempest-ipv6-only:
             irrelevant-files:
               - ^.*\.rst$
diff --git a/lib/tempest b/lib/tempest
index 81e96a2639..9e987a7adf 100644
--- a/lib/tempest
+++ b/lib/tempest
@@ -129,6 +129,13 @@ function set_tempest_venv_constraints {
         (cd $REQUIREMENTS_DIR &&
             git show master:upper-constraints.txt 2>/dev/null ||
             git show origin/master:upper-constraints.txt) > $tmp_c
+        # NOTE(gmann): we need to set the below env var pointing to master
+        # constraints even that is what default in tox.ini. Otherwise it can
+        # create the issue for grenade run where old and new devstack can have
+        # different tempest (old and master) to install. For detail problem,
+        # refer to the https://bugs.launchpad.net/devstack/+bug/2003993
+        export UPPER_CONSTRAINTS_FILE=https://releases.openstack.org/constraints/upper/master
+        export TOX_CONSTRAINTS_FILE=https://releases.openstack.org/constraints/upper/master
     else
         echo "Using $TEMPEST_VENV_UPPER_CONSTRAINTS constraints in Tempest virtual env."
         cat $TEMPEST_VENV_UPPER_CONSTRAINTS > $tmp_c