diff --git a/cortex/alertmanager.libsonnet b/cortex/alertmanager.libsonnet
index 480112d..47cb340 100644
--- a/cortex/alertmanager.libsonnet
+++ b/cortex/alertmanager.libsonnet
@@ -50,7 +50,7 @@
     gossip_single_replica: {
       ports: [],
       args: {},
-      flags: ['--alertmanager.cluster.listen-address=""'],
+      flags: ['--alertmanager.cluster.listen-address='],
       service: $.util.serviceFor($.alertmanager_statefulset),
     },
   }[haType],