diff --git a/ansible/roles/prometheus/templates/prometheus.yml.j2 b/ansible/roles/prometheus/templates/prometheus.yml.j2
index 915e3f7e95..a5d9080669 100644
--- a/ansible/roles/prometheus/templates/prometheus.yml.j2
+++ b/ansible/roles/prometheus/templates/prometheus.yml.j2
@@ -254,9 +254,9 @@ scrape_configs:
 
 alerting:
   alertmanagers:
-  - static_configs:
-    - targets:
+    - static_configs:
 {% for host in groups["prometheus-alertmanager"] %}
+      - targets:
         - '{{ 'api' | kolla_address(host) | put_address_in_context('url') }}:{{ hostvars[host]['prometheus_alertmanager_port'] }}'
 {% if hostvars[host].prometheus_instance_label | default(false, true) %}
         labels:
diff --git a/releasenotes/notes/prometheus-template-fix-b971aad477a8fdc9.yaml b/releasenotes/notes/prometheus-template-fix-b971aad477a8fdc9.yaml
new file mode 100644
index 0000000000..5aade4453f
--- /dev/null
+++ b/releasenotes/notes/prometheus-template-fix-b971aad477a8fdc9.yaml
@@ -0,0 +1,5 @@
+---
+fixes:
+  - |
+    Fixed an issue with the ``prometheus.yml`` template which would break when
+    deploying alertmanager.