diff --git a/include/proto/server.h b/include/proto/server.h
index 9467f69..82c9cbf 100644
--- a/include/proto/server.h
+++ b/include/proto/server.h
@@ -252,7 +252,7 @@
 			return 0;
 		}
 		LIST_DEL(&conn->list);
-		LIST_ADDQ(&srv->idle_orphan_conns[tid], &conn->list);
+		LIST_ADDQ_LOCKED(&srv->idle_orphan_conns[tid], &conn->list);
 		srv->curr_idle_thr[tid]++;
 
 		conn->idle_time = now_ms;