diff --git a/src/os/unix/ngx_process.h b/src/os/unix/ngx_process.h
index 819064b..1ce39e5 100644
--- a/src/os/unix/ngx_process.h
+++ b/src/os/unix/ngx_process.h
@@ -9,6 +9,7 @@
 typedef struct {
     ngx_pid_t           pid;
     int                 status;
+    ngx_socket_t        channel[2];
 
     ngx_spawn_proc_pt   proc;
     void               *data;
@@ -48,7 +49,8 @@
 void ngx_process_get_status(void);
 
 extern ngx_pid_t      ngx_pid;
-extern ngx_uint_t     ngx_last_process;
+extern ngx_int_t      ngx_last_process;
+extern ngx_socket_t   ngx_channel;
 extern ngx_process_t  ngx_processes[NGX_MAX_PROCESSES];