diff --git a/src/os/unix/ngx_socket.h b/src/os/unix/ngx_socket.h
index cee1f4a..2a412d3 100644
--- a/src/os/unix/ngx_socket.h
+++ b/src/os/unix/ngx_socket.h
@@ -13,7 +13,7 @@
 #define ngx_socket_n        "socket()"
 
 
-#if 1
+#if (HAVE_FIONBIO)
 
 int ngx_nonblocking(ngx_socket_t s);
 int ngx_blocking(ngx_socket_t s);
@@ -28,6 +28,13 @@
 
 #endif
 
+int ngx_tcp_nopush(ngx_socket_t s);
+#define ngx_tcp_nopush_n   "setsockopt(TCP_NOPUSH)"
+
+int ngx_tcp_push(ngx_socket_t s);
+#define ngx_tcp_push_n     "setsockopt(!TCP_NOPUSH)"
+
+
 
 #define ngx_shutdown_socket    shutdown
 #define ngx_shutdown_socket_n  "shutdown()"