diff --git a/src/http/ngx_http_upstream_round_robin.c b/src/http/ngx_http_upstream_round_robin.c
index 52da545a1..487b0e3cc 100644
--- a/src/http/ngx_http_upstream_round_robin.c
+++ b/src/http/ngx_http_upstream_round_robin.c
@@ -599,17 +599,20 @@ ngx_http_upstream_free_round_robin_peer(ngx_peer_connection_t *pc, void *data,
 
     peer = rrp->current;
 
+    ngx_http_upstream_rr_peers_rlock(rrp->peers);
+    ngx_http_upstream_rr_peer_lock(rrp->peers, peer);
+
     if (rrp->peers->single) {
 
         peer->conns--;
 
+        ngx_http_upstream_rr_peer_unlock(rrp->peers, peer);
+        ngx_http_upstream_rr_peers_unlock(rrp->peers);
+
         pc->tries = 0;
         return;
     }
 
-    ngx_http_upstream_rr_peers_rlock(rrp->peers);
-    ngx_http_upstream_rr_peer_lock(rrp->peers, peer);
-
     if (state & NGX_PEER_FAILED) {
         now = ngx_time();