diff --git a/evdns.c b/evdns.c
index 152ba766..905ff6b5 100644
--- a/evdns.c
+++ b/evdns.c
@@ -4009,7 +4009,7 @@ static void
 evdns_nameserver_free(struct nameserver *server)
 {
 	if (server->socket >= 0)
-	evutil_closesocket(server->socket);
+		evutil_closesocket(server->socket);
 	(void) event_del(&server->event);
 	event_debug_unassign(&server->event);
 	if (server->state == 0)
@@ -4049,6 +4049,8 @@ evdns_base_free_and_unlock(struct evdns_base *base, int fail_requests)
 
 	for (server = base->server_head; server; server = server_next) {
 		server_next = server->next;
+		/** already done something before */
+		server->probe_request = NULL;
 		evdns_nameserver_free(server);
 		if (server_next == base->server_head)
 			break;