--- a/src/http/ngx_http_upstream.c
+++ b/src/http/ngx_http_upstream.c
@@ -55,6 +55,8 @@ static ngx_int_t ngx_http_upstream_inter
 static ngx_int_t ngx_http_upstream_test_connect(ngx_connection_t *c);
 static ngx_int_t ngx_http_upstream_process_headers(ngx_http_request_t *r,
     ngx_http_upstream_t *u);
+static ngx_int_t ngx_http_upstream_process_trailers(ngx_http_request_t *r,
+    ngx_http_upstream_t *u);
 static void ngx_http_upstream_send_response(ngx_http_request_t *r,
     ngx_http_upstream_t *u);
 static void ngx_http_upstream_upgrade(ngx_http_request_t *r,
@@ -164,6 +166,8 @@ static ngx_int_t ngx_http_upstream_respo
     ngx_http_request_t *r, ngx_http_variable_value_t *v, uintptr_t data);
 static ngx_int_t ngx_http_upstream_header_variable(ngx_http_request_t *r,
     ngx_http_variable_value_t *v, uintptr_t data);
+static ngx_int_t ngx_http_upstream_trailer_variable(ngx_http_request_t *r,
+    ngx_http_variable_value_t *v, uintptr_t data);
 static ngx_int_t ngx_http_upstream_cookie_variable(ngx_http_request_t *r,
     ngx_http_variable_value_t *v, uintptr_t data);
 
@@ -423,6 +427,9 @@ static ngx_http_variable_t  ngx_http_ups
     { ngx_string("upstream_http_"), NULL, ngx_http_upstream_header_variable,
       0, NGX_HTTP_VAR_NOCACHEABLE|NGX_HTTP_VAR_PREFIX, 0 },
 
+    { ngx_string("upstream_trailer_"), NULL, ngx_http_upstream_trailer_variable,
+      0, NGX_HTTP_VAR_NOCACHEABLE|NGX_HTTP_VAR_PREFIX, 0 },
+
     { ngx_string("upstream_cookie_"), NULL, ngx_http_upstream_cookie_variable,
       0, NGX_HTTP_VAR_NOCACHEABLE|NGX_HTTP_VAR_PREFIX, 0 },
 
@@ -1046,6 +1053,13 @@ ngx_http_upstream_cache_send(ngx_http_re
         return NGX_ERROR;
     }
 
+    if (ngx_list_init(&u->headers_in.trailers, r->pool, 2,
+                      sizeof(ngx_table_elt_t))
+        != NGX_OK)
+    {
+        return NGX_ERROR;
+    }
+
     rc = u->process_header(r);
 
     if (rc == NGX_OK) {
@@ -1883,6 +1897,13 @@ ngx_http_upstream_reinit(ngx_http_reques
         return NGX_ERROR;
     }
 
+    if (ngx_list_init(&u->headers_in.trailers, r->pool, 2,
+                      sizeof(ngx_table_elt_t))
+        != NGX_OK)
+    {
+        return NGX_ERROR;
+    }
+
     /* reinit the request chain */
 
     file_pos = 0;
@@ -2237,6 +2258,15 @@ ngx_http_upstream_process_header(ngx_htt
             return;
         }
 
+        if (ngx_list_init(&u->headers_in.trailers, r->pool, 2,
+                          sizeof(ngx_table_elt_t))
+            != NGX_OK)
+        {
+            ngx_http_upstream_finalize_request(r, u,
+                                               NGX_HTTP_INTERNAL_SERVER_ERROR);
+            return;
+        }
+
 #if (NGX_HTTP_CACHE)
 
         if (r->cache) {
@@ -2735,6 +2765,51 @@ ngx_http_upstream_process_headers(ngx_ht
 }
 
 
+static ngx_int_t
+ngx_http_upstream_process_trailers(ngx_http_request_t *r,
+    ngx_http_upstream_t *u)
+{
+    ngx_uint_t        i;
+    ngx_list_part_t  *part;
+    ngx_table_elt_t  *h, *ho;
+
+    if (!u->conf->pass_trailers) {
+        return NGX_OK;
+    }
+
+    part = &u->headers_in.trailers.part;
+    h = part->elts;
+
+    for (i = 0; /* void */; i++) {
+
+        if (i >= part->nelts) {
+            if (part->next == NULL) {
+                break;
+            }
+
+            part = part->next;
+            h = part->elts;
+            i = 0;
+        }
+
+        if (ngx_hash_find(&u->conf->hide_headers_hash, h[i].hash,
+                          h[i].lowcase_key, h[i].key.len))
+        {
+            continue;
+        }
+
+        ho = ngx_list_push(&r->headers_out.trailers);
+        if (ho == NULL) {
+            return NGX_ERROR;
+        }
+
+        *ho = h[i];
+    }
+
+    return NGX_OK;
+}
+
+
 static void
 ngx_http_upstream_send_response(ngx_http_request_t *r, ngx_http_upstream_t *u)
 {
@@ -4272,6 +4347,12 @@ ngx_http_upstream_finalize_request(ngx_h
     }
 
     if (rc == 0) {
+
+        if (ngx_http_upstream_process_trailers(r, u) != NGX_OK) {
+            ngx_http_finalize_request(r, NGX_ERROR);
+            return;
+        }
+
         rc = ngx_http_send_special(r, NGX_HTTP_LAST);
 
     } else if (flush) {
@@ -5382,6 +5463,21 @@ ngx_http_upstream_header_variable(ngx_ht
 
 
 static ngx_int_t
+ngx_http_upstream_trailer_variable(ngx_http_request_t *r,
+    ngx_http_variable_value_t *v, uintptr_t data)
+{
+    if (r->upstream == NULL) {
+        v->not_found = 1;
+        return NGX_OK;
+    }
+
+    return ngx_http_variable_unknown_header(v, (ngx_str_t *) data,
+                                        &r->upstream->headers_in.trailers.part,
+                                        sizeof("upstream_trailer_") - 1);
+}
+
+
+static ngx_int_t
 ngx_http_upstream_cookie_variable(ngx_http_request_t *r,
     ngx_http_variable_value_t *v, uintptr_t data)
 {

--- a/src/http/ngx_http_upstream.h
+++ b/src/http/ngx_http_upstream.h
@@ -222,6 +222,7 @@ typedef struct {
     signed                           store:2;
     unsigned                         intercept_404:1;
     unsigned                         change_buffering:1;
+    unsigned                         pass_trailers:1;
 
 #if (NGX_HTTP_SSL || NGX_COMPAT)
     ngx_ssl_t                       *ssl;
@@ -251,6 +252,7 @@ typedef struct {
 
 typedef struct {
     ngx_list_t                       headers;
+    ngx_list_t                       trailers;
 
     ngx_uint_t                       status_n;
     ngx_str_t                        status_line;