diff --git src/http/modules/ngx_http_upstream_hash_module.c src/http/modules/ngx_http_upstream_hash_module.c
index 1e2e05c..44a72e2 100644
--- src/http/modules/ngx_http_upstream_hash_module.c
+++ src/http/modules/ngx_http_upstream_hash_module.c
@@ -9,6 +9,9 @@
 #include <ngx_core.h>
 #include <ngx_http.h>
 
+#if (NGX_HTTP_UPSTREAM_CHECK)
+#include "ngx_http_upstream_check_module.h"
+#endif
 
 typedef struct {
     uint32_t                            hash;
@@ -235,6 +238,15 @@ ngx_http_upstream_get_hash_peer(ngx_peer_connection_t *pc, void *data)
             goto next;
         }
 
+#if (NGX_HTTP_UPSTREAM_CHECK)
+        ngx_log_debug1(NGX_LOG_DEBUG_HTTP, pc->log, 0,
+            "get hash peer, check_index: %ui",
+             peer->check_index);
+        if (ngx_http_upstream_check_peer_down(peer->check_index)) {
+            goto next;
+        }
+#endif
+
         if (peer->max_fails
             && peer->fails >= peer->max_fails
             && now - peer->checked <= peer->fail_timeout)
@@ -535,6 +547,15 @@ ngx_http_upstream_get_chash_peer(ngx_peer_connection_t *pc, void *data)
                 continue;
             }
 
+#if (NGX_HTTP_UPSTREAM_CHECK)
+            ngx_log_debug1(NGX_LOG_DEBUG_HTTP, pc->log, 0,
+                "get consistent_hash peer, check_index: %ui",
+                 peer->check_index);
+            if (ngx_http_upstream_check_peer_down(peer->check_index)) {
+                continue;
+            }
+#endif
+
             if (peer->server.len != server->len
                 || ngx_strncmp(peer->server.data, server->data, server->len)
                    != 0)
diff --git src/http/modules/ngx_http_upstream_ip_hash_module.c src/http/modules/ngx_http_upstream_ip_hash_module.c
index 401b58e..ba656bd 100644
--- src/http/modules/ngx_http_upstream_ip_hash_module.c
+++ src/http/modules/ngx_http_upstream_ip_hash_module.c
@@ -9,6 +9,9 @@
 #include <ngx_core.h>
 #include <ngx_http.h>
 
+#if (NGX_HTTP_UPSTREAM_CHECK)
+#include "ngx_http_upstream_check_module.h"
+#endif
 
 typedef struct {
     /* the round robin data must be first */
@@ -205,6 +208,15 @@ ngx_http_upstream_get_ip_hash_peer(ngx_peer_connection_t *pc, void *data)
             goto next;
         }
 
+#if (NGX_HTTP_UPSTREAM_CHECK)
+        ngx_log_debug1(NGX_LOG_DEBUG_HTTP, pc->log, 0,
+            "get ip_hash peer, check_index: %ui",
+             peer->check_index);
+        if (ngx_http_upstream_check_peer_down(peer->check_index)) {
+            goto next;
+        }
+#endif
+
         if (peer->max_fails
             && peer->fails >= peer->max_fails
             && now - peer->checked <= peer->fail_timeout)
diff --git src/http/modules/ngx_http_upstream_least_conn_module.c src/http/modules/ngx_http_upstream_least_conn_module.c
index 92951bd..48aca2c 100644
--- src/http/modules/ngx_http_upstream_least_conn_module.c
+++ src/http/modules/ngx_http_upstream_least_conn_module.c
@@ -9,6 +9,9 @@
 #include <ngx_core.h>
 #include <ngx_http.h>
 
+#if (NGX_HTTP_UPSTREAM_CHECK)
+#include "ngx_http_upstream_check_module.h"
+#endif
 
 static ngx_int_t ngx_http_upstream_init_least_conn_peer(ngx_http_request_t *r,
     ngx_http_upstream_srv_conf_t *us);
@@ -148,6 +151,16 @@ ngx_http_upstream_get_least_conn_peer(ngx_peer_connection_t *pc, void *data)
             continue;
         }
 
+#if (NGX_HTTP_UPSTREAM_CHECK)
+        ngx_log_debug1(NGX_LOG_DEBUG_HTTP, pc->log, 0,
+                "get least_conn peer, check_index: %ui",
+                peer->check_index);
+
+        if (ngx_http_upstream_check_peer_down(peer->check_index)) {
+            continue;
+        }
+#endif
+
         if (peer->max_fails
             && peer->fails >= peer->max_fails
             && now - peer->checked <= peer->fail_timeout)
@@ -199,6 +212,16 @@ ngx_http_upstream_get_least_conn_peer(ngx_peer_connection_t *pc, void *data)
                 continue;
             }
 
+#if (NGX_HTTP_UPSTREAM_CHECK)
+            ngx_log_debug1(NGX_LOG_DEBUG_HTTP, pc->log, 0,
+                    "get least_conn peer, check_index: %ui",
+                    peer->check_index);
+
+            if (ngx_http_upstream_check_peer_down(peer->check_index)) {
+                continue;
+            }
+#endif
+
             if (peer->conns * best->weight != best->conns * peer->weight) {
                 continue;
             }
diff --git src/http/ngx_http_upstream_round_robin.c src/http/ngx_http_upstream_round_robin.c
index d6ae33b..416572a 100644
--- src/http/ngx_http_upstream_round_robin.c
+++ src/http/ngx_http_upstream_round_robin.c
@@ -9,6 +9,9 @@
 #include <ngx_core.h>
 #include <ngx_http.h>
 
+#if (NGX_HTTP_UPSTREAM_CHECK)
+#include "ngx_http_upstream_check_module.h"
+#endif
 
 #define ngx_http_upstream_tries(p) ((p)->number                               \
                                     + ((p)->next ? (p)->next->number : 0))
@@ -96,7 +99,14 @@ ngx_http_upstream_init_round_robin(ngx_conf_t *cf,
                 peer[n].fail_timeout = server[i].fail_timeout;
                 peer[n].down = server[i].down;
                 peer[n].server = server[i].name;
-
+#if (NGX_HTTP_UPSTREAM_CHECK)
+                if (!server[i].down) {
+                    peer[n].check_index =
+                        ngx_http_upstream_check_add_peer(cf, us, &server[i].addrs[j]);
+                } else {
+                    peer[n].check_index = (ngx_uint_t) NGX_ERROR;
+                }
+#endif
                 *peerp = &peer[n];
                 peerp = &peer[n].next;
                 n++;
@@ -159,7 +169,15 @@ ngx_http_upstream_init_round_robin(ngx_conf_t *cf,
                 peer[n].fail_timeout = server[i].fail_timeout;
                 peer[n].down = server[i].down;
                 peer[n].server = server[i].name;
-
+#if (NGX_HTTP_UPSTREAM_CHECK)
+                if (!server[i].down) {
+                    peer[n].check_index =
+                        ngx_http_upstream_check_add_peer(cf, us, &server[i].addrs[j]);
+                }
+                else {
+                    peer[n].check_index = (ngx_uint_t) NGX_ERROR;
+                }
+#endif
                 *peerp = &peer[n];
                 peerp = &peer[n].next;
                 n++;
@@ -225,6 +243,9 @@ ngx_http_upstream_init_round_robin(ngx_conf_t *cf,
         peer[i].current_weight = 0;
         peer[i].max_fails = 1;
         peer[i].fail_timeout = 10;
+#if (NGX_HTTP_UPSTREAM_CHECK)
+        peer[i].check_index = (ngx_uint_t) NGX_ERROR;
+#endif
         *peerp = &peer[i];
         peerp = &peer[i].next;
     }
@@ -339,6 +360,9 @@ ngx_http_upstream_create_round_robin_peer(ngx_http_request_t *r,
         peer[0].current_weight = 0;
         peer[0].max_fails = 1;
         peer[0].fail_timeout = 10;
+#if (NGX_HTTP_UPSTREAM_CHECK)
+        peer[0].check_index = (ngx_uint_t) NGX_ERROR;
+#endif
         peers->peer = peer;
 
     } else {
@@ -381,6 +405,9 @@ ngx_http_upstream_create_round_robin_peer(ngx_http_request_t *r,
             peer[i].current_weight = 0;
             peer[i].max_fails = 1;
             peer[i].fail_timeout = 10;
+#if (NGX_HTTP_UPSTREAM_CHECK)
+            peer[i].check_index = (ngx_uint_t) NGX_ERROR;
+#endif
             *peerp = &peer[i];
             peerp = &peer[i].next;
         }
@@ -441,6 +468,12 @@ ngx_http_upstream_get_round_robin_peer(ngx_peer_connection_t *pc, void *data)
             goto failed;
         }
 
+#if (NGX_HTTP_UPSTREAM_CHECK)
+        if (ngx_http_upstream_check_peer_down(peer->check_index)) {
+            goto failed;
+        }
+#endif
+
         rrp->current = peer;
 
     } else {
@@ -542,6 +575,12 @@ ngx_http_upstream_get_peer(ngx_http_upstream_rr_peer_data_t *rrp)
             continue;
         }
 
+#if (NGX_HTTP_UPSTREAM_CHECK)
+        if (ngx_http_upstream_check_peer_down(peer->check_index)) {
+            continue;
+        }
+#endif
+
         if (peer->max_fails
             && peer->fails >= peer->max_fails
             && now - peer->checked <= peer->fail_timeout)
diff --git src/http/ngx_http_upstream_round_robin.h src/http/ngx_http_upstream_round_robin.h
index f2c573f..75e0ed6 100644
--- src/http/ngx_http_upstream_round_robin.h
+++ src/http/ngx_http_upstream_round_robin.h
@@ -35,6 +35,10 @@ struct ngx_http_upstream_rr_peer_s {
     ngx_uint_t                      max_fails;
     time_t                          fail_timeout;
 
+#if (NGX_HTTP_UPSTREAM_CHECK)
+    ngx_uint_t                      check_index;
+#endif
+
     ngx_uint_t                      down;          /* unsigned  down:1; */
 
 #if (NGX_HTTP_SSL)