diff --git a/files/ansible-playbooks/update-reboot-scheduler.yml b/files/ansible-playbooks/update-reboot-scheduler.yml
index d2eda5f..f37fc56 100644
--- a/files/ansible-playbooks/update-reboot-scheduler.yml
+++ b/files/ansible-playbooks/update-reboot-scheduler.yml
@@ -41,7 +41,9 @@
         _lines: "{{ (nb_preflight.stdout_lines | default([])) | map('regex_replace','\r','') | map('trim') | list }}"
         _ok_line: "{{ (_lines | select('match','^OK\\s+') | list | last | default('')) }}"
         _fail_line: "{{ (_lines | select('match','^FAIL\\s+') | list | last | default('')) }}"
-        _ip_raw: "{{ _ok_line | regex_search('([0-9]{1,3}(?:\\.[0-9]{1,3}){3})','\\1') | default('') }}"
+        # NOTE: regex_search with a replacement can yield a list on some Ansible/Jinja versions;
+        # keep it as a plain string match for ansible_host.
+        _ip_raw: "{{ _ok_line | regex_search('([0-9]{1,3}(?:\\.[0-9]{1,3}){3})') | default('') }}"
       set_fact:
         nb_ip: "{{ _ip_raw }}"
         nb_ip_ok: "{{ (_ip_raw | length) > 0 }}"