diff --git a/jsonnet/kube-prometheus/alerts/alertmanager.libsonnet b/jsonnet/kube-prometheus/alerts/alertmanager.libsonnet
index c2e440c50bab2a4db9d135c9a8a2552c00590e08..c8aba879c33dfbc7286292cdc1671e61cec9a23a 100644
--- a/jsonnet/kube-prometheus/alerts/alertmanager.libsonnet
+++ b/jsonnet/kube-prometheus/alerts/alertmanager.libsonnet
@@ -10,7 +10,7 @@
               message: 'The configuration of the instances of the Alertmanager cluster `{{$labels.service}}` are out of sync.',
             },
             expr: |||
-              count_values("config_hash", alertmanager_config_hash{%(alertmanagerSelector)s}) BY (service) / ON(service) GROUP_LEFT() label_replace(prometheus_operator_spec_replicas{%(prometheusOperatorSelector)s}, "service", "alertmanager-$1", "alertmanager", "(.*)") != 1
+              count_values("config_hash", alertmanager_config_hash{%(alertmanagerSelector)s}) BY (service) / ON(service) GROUP_LEFT() label_replace(prometheus_operator_spec_replicas{%(prometheusOperatorSelector)s,controller="alertmanager"}, "service", "alertmanager-$1", "name", "(.*)") != 1
             ||| % $._config,
             'for': '5m',
             labels: {