diff --git a/puppet/zulip_ops/files/nagios3/nagios.cfg b/puppet/zulip_ops/files/nagios3/nagios.cfg
index 4f7e430483..4fc28c1b12 100644
--- a/puppet/zulip_ops/files/nagios3/nagios.cfg
+++ b/puppet/zulip_ops/files/nagios3/nagios.cfg
@@ -1323,4 +1323,5 @@ debug_file=/var/log/nagios3/nagios.debug
 
 max_debug_file_size=1000000
 
+allow_empty_hostgroup_assignment=1