diff --git a/src/core/ngx_connection.c b/src/core/ngx_connection.c
index dc60679..61ea4c2 100644
--- a/src/core/ngx_connection.c
+++ b/src/core/ngx_connection.c
@@ -281,6 +281,22 @@ ngx_set_inherited_sockets(ngx_cycle_t *cycle)
         reuseport = 0;
         olen = sizeof(int);
 
+#ifdef SO_REUSEPORT_LB
+
+        if (getsockopt(ls[i].fd, SOL_SOCKET, SO_REUSEPORT_LB,
+                       (void *) &reuseport, &olen)
+            == -1)
+        {
+            ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_socket_errno,
+                          "getsockopt(SO_REUSEPORT_LB) %V failed, ignored",
+                          &ls[i].addr_text);
+
+        } else {
+            ls[i].reuseport = reuseport ? 1 : 0;
+        }
+
+#else
+
         if (getsockopt(ls[i].fd, SOL_SOCKET, SO_REUSEPORT,
                        (void *) &reuseport, &olen)
             == -1)
@@ -292,6 +308,7 @@ ngx_set_inherited_sockets(ngx_cycle_t *cycle)
         } else {
             ls[i].reuseport = reuseport ? 1 : 0;
         }
+#endif
 
 #endif
 
@@ -430,6 +447,20 @@ ngx_open_listening_sockets(ngx_cycle_t *cycle)
 
                 int  reuseport = 1;
 
+#ifdef SO_REUSEPORT_LB
+
+                if (setsockopt(ls[i].fd, SOL_SOCKET, SO_REUSEPORT_LB,
+                               (const void *) &reuseport, sizeof(int))
+                    == -1)
+                {
+                    ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_socket_errno,
+                                  "setsockopt(SO_REUSEPORT_LB) %V failed, "
+                                  "ignored",
+                                  &ls[i].addr_text);
+                }
+
+#else
+
                 if (setsockopt(ls[i].fd, SOL_SOCKET, SO_REUSEPORT,
                                (const void *) &reuseport, sizeof(int))
                     == -1)
@@ -438,6 +469,7 @@ ngx_open_listening_sockets(ngx_cycle_t *cycle)
                                   "setsockopt(SO_REUSEPORT) %V failed, ignored",
                                   &ls[i].addr_text);
                 }
+#endif
 
                 ls[i].add_reuseport = 0;
             }
@@ -488,6 +520,27 @@ ngx_open_listening_sockets(ngx_cycle_t *cycle)
 
                 reuseport = 1;
 
+#ifdef SO_REUSEPORT_LB
+
+                if (setsockopt(s, SOL_SOCKET, SO_REUSEPORT_LB,
+                               (const void *) &reuseport, sizeof(int))
+                    == -1)
+                {
+                    ngx_log_error(NGX_LOG_EMERG, log, ngx_socket_errno,
+                                  "setsockopt(SO_REUSEPORT_LB) %V failed",
+                                  &ls[i].addr_text);
+
+                    if (ngx_close_socket(s) == -1) {
+                        ngx_log_error(NGX_LOG_EMERG, log, ngx_socket_errno,
+                                      ngx_close_socket_n " %V failed",
+                                      &ls[i].addr_text);
+                    }
+
+                    return NGX_ERROR;
+                }
+
+#else
+
                 if (setsockopt(s, SOL_SOCKET, SO_REUSEPORT,
                                (const void *) &reuseport, sizeof(int))
                     == -1)
@@ -504,6 +557,7 @@ ngx_open_listening_sockets(ngx_cycle_t *cycle)
 
                     return NGX_ERROR;
                 }
+#endif
             }
 #endif
 
diff --git a/src/http/modules/ngx_http_grpc_module.c b/src/http/modules/ngx_http_grpc_module.c
index 300d927..0baa85f 100644
--- a/src/http/modules/ngx_http_grpc_module.c
+++ b/src/http/modules/ngx_http_grpc_module.c
@@ -3868,6 +3868,7 @@ ngx_http_grpc_send_window_update(ngx_http_request_t *r,
 static ngx_chain_t *
 ngx_http_grpc_get_buf(ngx_http_request_t *r, ngx_http_grpc_ctx_t *ctx)
 {
+    u_char       *start;
     ngx_buf_t    *b;
     ngx_chain_t  *cl;
 
@@ -3877,29 +3878,33 @@ ngx_http_grpc_get_buf(ngx_http_request_t *r, ngx_http_grpc_ctx_t *ctx)
     }
 
     b = cl->buf;
+    start = b->start;
 
-    b->tag = (ngx_buf_tag_t) &ngx_http_grpc_body_output_filter;
-    b->temporary = 1;
-    b->flush = 1;
-
-    if (b->start == NULL) {
+    if (start == NULL) {
 
         /*
          * each buffer is large enough to hold two window update
          * frames in a row
          */
 
-        b->start = ngx_palloc(r->pool, 2 * sizeof(ngx_http_grpc_frame_t) + 8);
-        if (b->start == NULL) {
+        start = ngx_palloc(r->pool, 2 * sizeof(ngx_http_grpc_frame_t) + 8);
+        if (start == NULL) {
             return NULL;
         }
 
-        b->pos = b->start;
-        b->last = b->start;
-
-        b->end = b->start + 2 * sizeof(ngx_http_grpc_frame_t) + 8;
     }
 
+    ngx_memzero(b, sizeof(ngx_buf_t));
+
+    b->start = start;
+    b->pos = start;
+    b->last = start;
+    b->end = start + 2 * sizeof(ngx_http_grpc_frame_t) + 8;
+
+    b->tag = (ngx_buf_tag_t) &ngx_http_grpc_body_output_filter;
+    b->temporary = 1;
+    b->flush = 1;
+
     return cl;
 }
 
diff --git a/src/http/ngx_http_upstream.c b/src/http/ngx_http_upstream.c
index 47cc6cc..aba1fbb 100644
--- a/src/http/ngx_http_upstream.c
+++ b/src/http/ngx_http_upstream.c
@@ -1556,6 +1556,10 @@ ngx_http_upstream_connect(ngx_http_request_t *r, ngx_http_upstream_t *u)
     c->sendfile &= r->connection->sendfile;
     u->output.sendfile = c->sendfile;
 
+    if (r->connection->tcp_nopush == NGX_TCP_NOPUSH_DISABLED) {
+        c->tcp_nopush = NGX_TCP_NOPUSH_DISABLED;
+    }
+
     if (c->pool == NULL) {
 
         /* we need separate pool here to be able to cache SSL connections */
@@ -2008,6 +2012,18 @@ ngx_http_upstream_send_request(ngx_http_request_t *r, ngx_http_upstream_t *u,
             return;
         }
 
+        if (c->write->ready && c->tcp_nopush == NGX_TCP_NOPUSH_SET) {
+            if (ngx_tcp_push(c->fd) == -1) {
+                ngx_log_error(NGX_LOG_CRIT, c->log, ngx_socket_errno,
+                              ngx_tcp_push_n " failed");
+                ngx_http_upstream_finalize_request(r, u,
+                                               NGX_HTTP_INTERNAL_SERVER_ERROR);
+                return;
+            }
+
+            c->tcp_nopush = NGX_TCP_NOPUSH_UNSET;
+        }
+
         return;
     }