diff --git a/src/core/ngx_conf_file.c b/src/core/ngx_conf_file.c
index 6084abb..f00cf01 100644
--- a/src/core/ngx_conf_file.c
+++ b/src/core/ngx_conf_file.c
@@ -934,7 +934,7 @@
 
     a = (ngx_array_t **) (p + cmd->offset);
 
-    if (*a == NULL) {
+    if (*a == NGX_CONF_UNSET_PTR) {
         *a = ngx_array_create(cf->pool, 4, sizeof(ngx_str_t));
         if (*a == NULL) {
             return NGX_CONF_ERROR;
diff --git a/src/http/modules/ngx_http_fastcgi_module.c b/src/http/modules/ngx_http_fastcgi_module.c
index acd5c90..8cfef63 100644
--- a/src/http/modules/ngx_http_fastcgi_module.c
+++ b/src/http/modules/ngx_http_fastcgi_module.c
@@ -1643,8 +1643,6 @@
      *     conf->upstream.next_upstream = 0;
      *     conf->upstream.temp_path = NULL;
      *     conf->upstream.hide_headers_hash = { NULL, 0 };
-     *     conf->upstream.hide_headers = NULL;
-     *     conf->upstream.pass_headers = NULL;
      *     conf->upstream.schema = { 0, NULL };
      *     conf->upstream.uri = { 0, NULL };
      *     conf->upstream.location = NULL;
@@ -1674,6 +1672,9 @@
     conf->upstream.pass_request_headers = NGX_CONF_UNSET;
     conf->upstream.pass_request_body = NGX_CONF_UNSET;
 
+    conf->upstream.hide_headers = NGX_CONF_UNSET_PTR;
+    conf->upstream.pass_headers = NGX_CONF_UNSET_PTR;
+
     conf->upstream.intercept_errors = NGX_CONF_UNSET;
 
     /* "fastcgi_cyclic_temp_file" is disabled */
@@ -1694,11 +1695,8 @@
     u_char                       *p;
     size_t                        size;
     uintptr_t                    *code;
-    ngx_str_t                    *header;
-    ngx_uint_t                    i, j;
-    ngx_array_t                   hide_headers;
+    ngx_uint_t                    i;
     ngx_keyval_t                 *src;
-    ngx_hash_key_t               *hk;
     ngx_hash_init_t               hash;
     ngx_http_script_compile_t     sc;
     ngx_http_script_copy_code_t  *copy;
@@ -1860,108 +1858,19 @@
 
     ngx_conf_merge_str_value(conf->index, prev->index, "");
 
-    if (conf->upstream.hide_headers == NULL
-        && conf->upstream.pass_headers == NULL)
-    {
-        conf->upstream.hide_headers = prev->upstream.hide_headers;
-        conf->upstream.pass_headers = prev->upstream.pass_headers;
-        conf->upstream.hide_headers_hash = prev->upstream.hide_headers_hash;
+    hash.max_size = 512;
+    hash.bucket_size = ngx_align(64, ngx_cacheline_size);
+    hash.name = "fastcgi_hide_headers_hash";
 
-        if (conf->upstream.hide_headers_hash.buckets) {
-            goto peers;
-        }
-
-    } else {
-        if (conf->upstream.hide_headers == NULL) {
-            conf->upstream.hide_headers = prev->upstream.hide_headers;
-        }
-
-        if (conf->upstream.pass_headers == NULL) {
-            conf->upstream.pass_headers = prev->upstream.pass_headers;
-        }
-    }
-
-    if (ngx_array_init(&hide_headers, cf->temp_pool, 4, sizeof(ngx_hash_key_t))
+    if (ngx_http_upstream_hide_headers_hash(cf, &conf->upstream,
+                                            &prev->upstream,
+                                            ngx_http_fastcgi_hide_headers,
+                                            &hash)
         != NGX_OK)
     {
         return NGX_CONF_ERROR;
     }
 
-    for (header = ngx_http_fastcgi_hide_headers; header->len; header++) {
-        hk = ngx_array_push(&hide_headers);
-        if (hk == NULL) {
-            return NGX_CONF_ERROR;
-        }
-
-        hk->key = *header;
-        hk->key_hash = ngx_hash_key_lc(header->data, header->len);
-        hk->value = (void *) 1;
-    }
-
-    if (conf->upstream.hide_headers) {
-
-        header = conf->upstream.hide_headers->elts;
-
-        for (i = 0; i < conf->upstream.hide_headers->nelts; i++) {
-
-            hk = hide_headers.elts;
-
-            for (j = 0; j < hide_headers.nelts; j++) {
-                if (ngx_strcasecmp(header[i].data, hk[j].key.data) == 0) {
-                    goto exist;
-                }
-            }
-
-            hk = ngx_array_push(&hide_headers);
-            if (hk == NULL) {
-                return NGX_CONF_ERROR;
-            }
-
-            hk->key = header[i];
-            hk->key_hash = ngx_hash_key_lc(header[i].data, header[i].len);
-            hk->value = (void *) 1;
-
-        exist:
-
-            continue;
-        }
-    }
-
-    if (conf->upstream.pass_headers) {
-
-        hk = hide_headers.elts;
-        header = conf->upstream.pass_headers->elts;
-
-        for (i = 0; i < conf->upstream.pass_headers->nelts; i++) {
-
-            for (j = 0; j < hide_headers.nelts; j++) {
-
-                if (hk[j].key.data == NULL) {
-                    continue;
-                }
-
-                if (ngx_strcasecmp(header[i].data, hk[j].key.data) == 0) {
-                    hk[j].key.data = NULL;
-                    break;
-                }
-            }
-        }
-    }
-
-    hash.hash = &conf->upstream.hide_headers_hash;
-    hash.key = ngx_hash_key_lc;
-    hash.max_size = 512;
-    hash.bucket_size = ngx_align(64, ngx_cacheline_size);
-    hash.name = "fastcgi_hide_headers_hash";
-    hash.pool = cf->pool;
-    hash.temp_pool = NULL;
-
-    if (ngx_hash_init(&hash, hide_headers.elts, hide_headers.nelts) != NGX_OK) {
-        return NGX_CONF_ERROR;
-    }
-
-peers:
-
     if (conf->upstream.upstream == NULL) {
         conf->upstream.upstream = prev->upstream.upstream;
         conf->upstream.schema = prev->upstream.schema;
diff --git a/src/http/modules/ngx_http_proxy_module.c b/src/http/modules/ngx_http_proxy_module.c
index 24da70d..ec31673 100644
--- a/src/http/modules/ngx_http_proxy_module.c
+++ b/src/http/modules/ngx_http_proxy_module.c
@@ -1634,8 +1634,6 @@
      *     conf->upstream.next_upstream = 0;
      *     conf->upstream.temp_path = NULL;
      *     conf->upstream.hide_headers_hash = { NULL, 0 };
-     *     conf->upstream.hide_headers = NULL;
-     *     conf->upstream.pass_headers = NULL;
      *     conf->upstream.schema = { 0, NULL };
      *     conf->upstream.uri = { 0, NULL };
      *     conf->upstream.location = NULL;
@@ -1672,6 +1670,9 @@
     conf->upstream.pass_request_headers = NGX_CONF_UNSET;
     conf->upstream.pass_request_body = NGX_CONF_UNSET;
 
+    conf->upstream.hide_headers = NGX_CONF_UNSET_PTR;
+    conf->upstream.pass_headers = NGX_CONF_UNSET_PTR;
+
     conf->upstream.intercept_errors = NGX_CONF_UNSET;
 
     /* "proxy_cyclic_temp_file" is disabled */
@@ -1696,9 +1697,7 @@
     u_char                       *p;
     size_t                        size;
     uintptr_t                    *code;
-    ngx_str_t                    *header;
-    ngx_uint_t                    i, j;
-    ngx_array_t                   hide_headers;
+    ngx_uint_t                    i;
     ngx_keyval_t                 *src, *s, *h;
     ngx_hash_key_t               *hk;
     ngx_hash_init_t               hash;
@@ -1913,107 +1912,18 @@
     conf->headers_hash_bucket_size = ngx_align(conf->headers_hash_bucket_size,
                                                ngx_cacheline_size);
 
-    if (conf->upstream.hide_headers == NULL
-        && conf->upstream.pass_headers == NULL)
-    {
-        conf->upstream.hide_headers = prev->upstream.hide_headers;
-        conf->upstream.pass_headers = prev->upstream.pass_headers;
-        conf->upstream.hide_headers_hash = prev->upstream.hide_headers_hash;
+    hash.max_size = conf->headers_hash_max_size;
+    hash.bucket_size = conf->headers_hash_bucket_size;
+    hash.name = "proxy_headers_hash";
 
-        if (conf->upstream.hide_headers_hash.buckets) {
-            goto peers;
-        }
-
-    } else {
-        if (conf->upstream.hide_headers == NULL) {
-            conf->upstream.hide_headers = prev->upstream.hide_headers;
-        }
-
-        if (conf->upstream.pass_headers == NULL) {
-            conf->upstream.pass_headers = prev->upstream.pass_headers;
-        }
-    }
-
-    if (ngx_array_init(&hide_headers, cf->temp_pool, 4, sizeof(ngx_hash_key_t))
+    if (ngx_http_upstream_hide_headers_hash(cf, &conf->upstream,
+                                            &prev->upstream,
+                                            ngx_http_proxy_hide_headers, &hash)
         != NGX_OK)
     {
         return NGX_CONF_ERROR;
     }
 
-    for (header = ngx_http_proxy_hide_headers; header->len; header++) {
-        hk = ngx_array_push(&hide_headers);
-        if (hk == NULL) {
-            return NGX_CONF_ERROR;
-        }
-
-        hk->key = *header;
-        hk->key_hash = ngx_hash_key_lc(header->data, header->len);
-        hk->value = (void *) 1;
-    }
-
-    if (conf->upstream.hide_headers) {
-
-        header = conf->upstream.hide_headers->elts;
-
-        for (i = 0; i < conf->upstream.hide_headers->nelts; i++) {
-
-            hk = hide_headers.elts;
-
-            for (j = 0; j < hide_headers.nelts; j++) {
-                if (ngx_strcasecmp(header[i].data, hk[j].key.data) == 0) {
-                    goto exist;
-                }
-            }
-
-            hk = ngx_array_push(&hide_headers);
-            if (hk == NULL) {
-                return NGX_CONF_ERROR;
-            }
-
-            hk->key = header[i];
-            hk->key_hash = ngx_hash_key_lc(header[i].data, header[i].len);
-            hk->value = (void *) 1;
-
-        exist:
-
-            continue;
-        }
-    }
-
-    if (conf->upstream.pass_headers) {
-
-        hk = hide_headers.elts;
-        header = conf->upstream.pass_headers->elts;
-
-        for (i = 0; i < conf->upstream.pass_headers->nelts; i++) {
-            for (j = 0; j < hide_headers.nelts; j++) {
-
-                if (hk[j].key.data == NULL) {
-                    continue;
-                }
-
-                if (ngx_strcasecmp(header[i].data, hk[j].key.data) == 0) {
-                    hk[j].key.data = NULL;
-                    break;
-                }
-            }
-        }
-    }
-
-    hash.hash = &conf->upstream.hide_headers_hash;
-    hash.key = ngx_hash_key_lc;
-    hash.max_size = conf->headers_hash_max_size;
-    hash.bucket_size = conf->headers_hash_bucket_size;
-    hash.name = "proxy_headers_hash";
-    hash.pool = cf->pool;
-    hash.temp_pool = NULL;
-
-    if (ngx_hash_init(&hash, hide_headers.elts, hide_headers.nelts) != NGX_OK) {
-        return NGX_CONF_ERROR;
-    }
-
-peers:
-
     if (conf->upstream.upstream == NULL) {
         conf->upstream.upstream = prev->upstream.upstream;
 
diff --git a/src/http/ngx_http_upstream.c b/src/http/ngx_http_upstream.c
index 48158a4..3cab8ef 100644
--- a/src/http/ngx_http_upstream.c
+++ b/src/http/ngx_http_upstream.c
@@ -3408,6 +3408,113 @@
 }
 
 
+ngx_int_t
+ngx_http_upstream_hide_headers_hash(ngx_conf_t *cf,
+    ngx_http_upstream_conf_t *conf, ngx_http_upstream_conf_t *prev,
+    ngx_str_t *default_hide_headers, ngx_hash_init_t *hash)
+{
+    ngx_str_t       *h;
+    ngx_uint_t       i, j;
+    ngx_array_t      hide_headers;
+    ngx_hash_key_t  *hk;
+
+    if (conf->hide_headers == NGX_CONF_UNSET_PTR
+        && conf->pass_headers == NGX_CONF_UNSET_PTR)
+    {
+        conf->hide_headers_hash = prev->hide_headers_hash;
+
+        if (conf->hide_headers_hash.buckets) {
+            return NGX_OK;
+        }
+
+        conf->hide_headers = prev->hide_headers;
+        conf->pass_headers = prev->pass_headers;
+
+    } else {
+        if (conf->hide_headers == NGX_CONF_UNSET_PTR) {
+            conf->hide_headers = prev->hide_headers;
+        }
+
+        if (conf->pass_headers == NGX_CONF_UNSET_PTR) {
+            conf->pass_headers = prev->pass_headers;
+        }
+    }
+
+    if (ngx_array_init(&hide_headers, cf->temp_pool, 4, sizeof(ngx_hash_key_t))
+        != NGX_OK)
+    {
+        return NGX_ERROR;
+    }
+
+    for (h = default_hide_headers; h->len; h++) {
+        hk = ngx_array_push(&hide_headers);
+        if (hk == NULL) {
+            return NGX_ERROR;
+        }
+
+        hk->key = *h;
+        hk->key_hash = ngx_hash_key_lc(h->data, h->len);
+        hk->value = (void *) 1;
+    }
+
+    if (conf->hide_headers != NGX_CONF_UNSET_PTR) {
+
+        h = conf->hide_headers->elts;
+
+        for (i = 0; i < conf->hide_headers->nelts; i++) {
+
+            hk = hide_headers.elts;
+
+            for (j = 0; j < hide_headers.nelts; j++) {
+                if (ngx_strcasecmp(h[i].data, hk[j].key.data) == 0) {
+                    goto exist;
+                }
+            }
+
+            hk = ngx_array_push(&hide_headers);
+            if (hk == NULL) {
+                return NGX_ERROR;
+            }
+
+            hk->key = h[i];
+            hk->key_hash = ngx_hash_key_lc(h[i].data, h[i].len);
+            hk->value = (void *) 1;
+
+        exist:
+
+            continue;
+        }
+    }
+
+    if (conf->pass_headers != NGX_CONF_UNSET_PTR) {
+
+        h = conf->pass_headers->elts;
+        hk = hide_headers.elts;
+
+        for (i = 0; i < conf->pass_headers->nelts; i++) {
+            for (j = 0; j < hide_headers.nelts; j++) {
+
+                if (hk[j].key.data == NULL) {
+                    continue;
+                }
+
+                if (ngx_strcasecmp(h[i].data, hk[j].key.data) == 0) {
+                    hk[j].key.data = NULL;
+                    break;
+                }
+            }
+        }
+    }
+
+    hash->hash = &conf->hide_headers_hash;
+    hash->key = ngx_hash_key_lc; 
+    hash->pool = cf->pool;
+    hash->temp_pool = NULL;
+    
+    return ngx_hash_init(hash, hide_headers.elts, hide_headers.nelts);
+}
+
+
 static void *
 ngx_http_upstream_create_main_conf(ngx_conf_t *cf)
 {
diff --git a/src/http/ngx_http_upstream.h b/src/http/ngx_http_upstream.h
index 8395362..a7a9a63 100644
--- a/src/http/ngx_http_upstream.h
+++ b/src/http/ngx_http_upstream.h
@@ -269,6 +269,9 @@
 void ngx_http_upstream_init(ngx_http_request_t *r);
 ngx_http_upstream_srv_conf_t *ngx_http_upstream_add(ngx_conf_t *cf,
     ngx_url_t *u, ngx_uint_t flags);
+ngx_int_t ngx_http_upstream_hide_headers_hash(ngx_conf_t *cf,
+    ngx_http_upstream_conf_t *conf, ngx_http_upstream_conf_t *prev,
+    ngx_str_t *default_hide_headers, ngx_hash_init_t *hash);
 
 
 #define ngx_http_conf_upstream_srv_conf(uscf, module)                         \