diff --git a/data/common/common.yaml b/data/common/common.yaml
--- a/data/common/common.yaml
+++ b/data/common/common.yaml
@@ -3164,6 +3164,7 @@
 prometheus::server::listen_network: "%{lookup('internal_network')}"
 prometheus::server::listen_port: 9090
 prometheus::server::certname: pergamon.softwareheritage.org
+prometheus::server::fqdn: pergamon.internal.softwareheritage.org
 
 swh::deploy::environment: production
 
diff --git a/site-modules/profile/manifests/icinga2/objects/agent_checks.pp b/site-modules/profile/manifests/icinga2/objects/agent_checks.pp
--- a/site-modules/profile/manifests/icinga2/objects/agent_checks.pp
+++ b/site-modules/profile/manifests/icinga2/objects/agent_checks.pp
@@ -1,8 +1,9 @@
 # Checks that need to be supported on icinga2 agents
 class profile::icinga2::objects::agent_checks {
 
+  $prometheus_host = lookup('prometheus::server::fqdn')
   $prometheus_port = lookup('prometheus::server::listen_port')
-  $prometheus_url = "pergamon.internal.softwareheritage.org:${prometheus_port}"
+  $prometheus_url = "http://${prometheus_host}:${prometheus_port}"
 
   $plugins = {
     'check_journal' => {