diff --git a/src/server.c b/src/server.c
index fe50fb9..df67e1d 100644
--- a/src/server.c
+++ b/src/server.c
@@ -5546,7 +5546,7 @@
 		if (srv->est_need_conns < srv->max_used_conns)
 			srv->est_need_conns = srv->max_used_conns;
 
-		srv->max_used_conns = srv->curr_used_conns;
+		HA_ATOMIC_STORE(&srv->max_used_conns, srv->curr_used_conns);
 
 		if (exceed_conns <= 0)
 			goto remove;