diff --git a/roles/prometheus/templates/prometheus-job.yml b/roles/prometheus/templates/prometheus-job.yml
index a6f045a..ad46f99 100644
--- a/roles/prometheus/templates/prometheus-job.yml
+++ b/roles/prometheus/templates/prometheus-job.yml
@@ -43,7 +43,8 @@
     - targets:
         {% for host in groups['all'] -%}
         {% if hostvars[host]['monitor_' + job.name] | default(false) | bool -%}
-        {%- set fstring = job.defaults | default({}) -%}
+        {%- set fstring = {} -%}
+        {%- set ignored = fstring.update(job.defaults|default({})) -%}
         {%- set ignored = fstring.update(hostvars[host]) -%}
         - {{ job.target_format | format(**fstring) }}
         {% endif -%}