diff --git a/zuul.d/xena_jobs.yaml b/zuul.d/xena_jobs.yaml
index 1e6eb80..e0a58a7 100644
--- a/zuul.d/xena_jobs.yaml
+++ b/zuul.d/xena_jobs.yaml
@@ -3,6 +3,7 @@
     parent: neutron-tempest-plugin-base
     override-checkout: stable/xena
     vars:
+      tempest_concurrency: 4
       tempest_test_regex: ^neutron_tempest_plugin\.api
       # TODO(slaweq): find a way to put this list of extensions in
       # neutron repository and keep it different per branch,