diff --git a/src/http/modules/ngx_http_proxy_module.c b/src/http/modules/ngx_http_proxy_module.c
index 644dacd..20b1109 100644
--- a/src/http/modules/ngx_http_proxy_module.c
+++ b/src/http/modules/ngx_http_proxy_module.c
@@ -1965,6 +1965,7 @@
                 ngx_str_set(&h->key, "Server");
                 ngx_str_null(&h->value);
                 h->lowcase_key = (u_char *) "server";
+                h->next = NULL;
             }
 
             if (r->upstream->headers_in.date == NULL) {
@@ -1978,6 +1979,7 @@
                 ngx_str_set(&h->key, "Date");
                 ngx_str_null(&h->value);
                 h->lowcase_key = (u_char *) "date";
+                h->next = NULL;
             }
 
             /* clear content length if response is chunked */
diff --git a/src/http/ngx_http_upstream.c b/src/http/ngx_http_upstream.c
index 73936f7..a111de8 100644
--- a/src/http/ngx_http_upstream.c
+++ b/src/http/ngx_http_upstream.c
@@ -4610,6 +4610,7 @@
 
     if (*ph == NULL) {
         *ph = h;
+        h->next = NULL;
     }
 
     return NGX_OK;
@@ -4632,6 +4633,7 @@
 
     u = r->upstream;
 
+    h->next = NULL;
     u->headers_in.content_length = h;
     u->headers_in.content_length_n = ngx_atoof(h->value.data, h->value.len);
 
@@ -4647,6 +4649,7 @@
 
     u = r->upstream;
 
+    h->next = NULL;
     u->headers_in.last_modified = h;
     u->headers_in.last_modified_time = ngx_parse_http_time(h->value.data,
                                                            h->value.len);
@@ -4816,6 +4819,7 @@
 
     u = r->upstream;
     u->headers_in.expires = h;
+    h->next = NULL;
 
 #if (NGX_HTTP_CACHE)
     {
@@ -4856,6 +4860,7 @@
 
     u = r->upstream;
     u->headers_in.x_accel_expires = h;
+    h->next = NULL;
 
 #if (NGX_HTTP_CACHE)
     {
@@ -4915,6 +4920,7 @@
 
     u = r->upstream;
     u->headers_in.x_accel_limit_rate = h;
+    h->next = NULL;
 
     if (u->conf->ignore_headers & NGX_HTTP_UPSTREAM_IGN_XA_LIMIT_RATE) {
         return NGX_OK;
@@ -4995,6 +5001,7 @@
 
     u = r->upstream;
     u->headers_in.connection = h;
+    h->next = NULL;
 
     if (ngx_strlcasestrn(h->value.data, h->value.data + h->value.len,
                          (u_char *) "close", 5 - 1)
@@ -5015,6 +5022,7 @@
 
     u = r->upstream;
     u->headers_in.transfer_encoding = h;
+    h->next = NULL;
 
     if (ngx_strlcasestrn(h->value.data, h->value.data + h->value.len,
                          (u_char *) "chunked", 7 - 1)
@@ -5035,6 +5043,7 @@
 
     u = r->upstream;
     u->headers_in.vary = h;
+    h->next = NULL;
 
 #if (NGX_HTTP_CACHE)