--- a/src/core/ngx_connection.c
+++ b/src/core/ngx_connection.c
@@ -282,6 +282,23 @@ ngx_open_listening_sockets(ngx_cycle_t *
                 return NGX_ERROR;
             }
 
+#if (NGX_HAVE_INET6 && defined IPV6_V6ONLY)
+
+            if (ls[i].sockaddr->sa_family == AF_INET6 && ls[i].ipv6only) {
+                int  ipv6only;
+
+                ipv6only = (ls[i].ipv6only == 1);
+
+                if (setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY,
+                               (const void *) &ipv6only, sizeof(int))
+                    == -1)
+                {
+                    ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_socket_errno,
+                                  "setsockopt(IPV6_V6ONLY) %V failed, ignored",
+                                  &ls[i].addr_text);
+                }
+            }
+#endif
             /* TODO: close on exit */
 
             if (!(ngx_event_flags & NGX_USE_AIO_EVENT)) {