diff --git a/puppet/zulip/files/nagios_plugins/zulip_app_frontend/check_send_receive_time b/puppet/zulip/files/nagios_plugins/zulip_app_frontend/check_send_receive_time
index d0909138fd..c376b08926 100755
--- a/puppet/zulip/files/nagios_plugins/zulip_app_frontend/check_send_receive_time
+++ b/puppet/zulip/files/nagios_plugins/zulip_app_frontend/check_send_receive_time
@@ -180,7 +180,7 @@ else:
         "to": recipient.email,
     })
 
-msg_content = [] # type: List[str]
+msg_content = []  # type: List[str]
 
 while msg_to_send not in msg_content:
     messages = get_zulips()