diff --git a/playbooks/proposal/propose_update.sh b/playbooks/proposal/propose_update.sh
index d0066f648d..c9110a23e1 100755
--- a/playbooks/proposal/propose_update.sh
+++ b/playbooks/proposal/propose_update.sh
@@ -38,8 +38,8 @@ elif [ "$OWN_PROJECT" == "requirements-constraints" ] ; then
     $VENV/bin/pip install -e .
     function update {
         $VENV/bin/generate-constraints -b blacklist.txt -p /usr/bin/python2.7 \
-            -p /usr/bin/python3 -r global-requirements.txt \
-            --version-map 3.4:3.5 --version-map 3.5:3.4 \
+            -p /usr/bin/python3.6 -r global-requirements.txt \
+            --version-map 3.6:3.4 --version-map 3.6:3.5 \
             > $1/upper-constraints.txt
     }
 elif [ "$OWN_PROJECT" == "devstack-plugins-list" ] ; then
diff --git a/zuul.d/projects.yaml b/zuul.d/projects.yaml
index 31e84519fe..5713c05cd6 100644
--- a/zuul.d/projects.yaml
+++ b/zuul.d/projects.yaml
@@ -12928,6 +12928,7 @@
               - publish-wheel-mirror-ubuntu-trusty
               - publish-wheel-mirror-ubuntu-xenial
         - propose-updates:
+            nodeset: ubuntu-bionic
             branches: master
             vars:
               update_target: requirements-constraints