diff --git a/roles/docker/tasks/set_facts_dns.yml b/roles/docker/tasks/set_facts_dns.yml
index ad30ba47f..7152b442b 100644
--- a/roles/docker/tasks/set_facts_dns.yml
+++ b/roles/docker/tasks/set_facts_dns.yml
@@ -49,7 +49,7 @@
 
 - name: add system search domains to docker options
   set_fact:
-    docker_dns_search_domains: "{{ docker_dns_search_domains | union(system_search_domains.stdout.split(' ')|default([])) | unique }}"
+    docker_dns_search_domains: "{{ docker_dns_search_domains | union(system_search_domains.stdout.split()|default([])) | unique }}"
   when: system_search_domains.stdout != ""
 
 - name: check number of nameservers