diff --git a/src/tcpcheck.c b/src/tcpcheck.c
index f889dff..896d4ee 100644
--- a/src/tcpcheck.c
+++ b/src/tcpcheck.c
@@ -913,6 +913,9 @@
 
 		cs += strlen("maxconn:");
 
+		/* This is safe to call server_parse_maxconn_change_request
+		 * because the server lock is held during the check.
+		 */
 		msg = server_parse_maxconn_change_request(check->server, cs);
 		if (!wrn || !*wrn)
 			wrn = msg;