diff --git a/playbooks/legacy/keystone-dsvm-grenade-multinode/run.yaml b/playbooks/legacy/keystone-dsvm-grenade-multinode/run.yaml
index 83131cec5b..1151879910 100644
--- a/playbooks/legacy/keystone-dsvm-grenade-multinode/run.yaml
+++ b/playbooks/legacy/keystone-dsvm-grenade-multinode/run.yaml
@@ -31,6 +31,7 @@
           export DEVSTACK_GATE_CONFIGDRIVE=0
           export DEVSTACK_GATE_NEUTRON=1
           export DEVSTACK_GATE_GRENADE=pullup
+          export DEVSTACK_GATE_USE_PYTHON3=True
           export PROJECTS="openstack/grenade $PROJECTS"
           export BRANCH_OVERRIDE=default
           if [ "$BRANCH_OVERRIDE" != "default" ] ; then