diff --git a/metadata/service/api/single.yml b/metadata/service/api/single.yml
index bde3356..affaab3 100644
--- a/metadata/service/api/single.yml
+++ b/metadata/service/api/single.yml
@@ -25,6 +25,8 @@
         address: ${_param:single_address}
         port: 6385
         protocol: 'http'
+      concurrency:
+        lock_path: '/var/lib/ironic/tmp'
       message_queue:
         engine: rabbitmq
         port: 5672