diff --git a/roles/ceph-osd/tasks/start_osds.yml b/roles/ceph-osd/tasks/start_osds.yml
index 3be380638..eccf05539 100644
--- a/roles/ceph-osd/tasks/start_osds.yml
+++ b/roles/ceph-osd/tasks/start_osds.yml
@@ -40,7 +40,7 @@
     enabled: yes
     masked: no
     daemon_reload: yes
-  with_items: "{{ ((ceph_osd_ids.stdout | default('{}') | from_json).keys() | list) + osd_ids_non_container.stdout_lines | default([]) }}"
+  with_items: "{{ ((ceph_osd_ids.stdout | default('{}') | from_json).keys() | list) | union(osd_ids_non_container.stdout_lines) | default([]) }}"
 
 - name: ensure systemd service override directory exists
   file: