--- a/src/core/ngx_cycle.h
+++ b/src/core/ngx_cycle.h
@@ -116,6 +116,7 @@ typedef struct {
 ngx_cycle_t *ngx_init_cycle(ngx_cycle_t *old_cycle);
 ngx_int_t ngx_create_pidfile(ngx_str_t *name, ngx_log_t *log);
 void ngx_delete_pidfile(ngx_cycle_t *cycle);
+ngx_int_t ngx_signal_process(ngx_cycle_t *cycle, char *sig);
 void ngx_reopen_files(ngx_cycle_t *cycle, ngx_uid_t user);
 char **ngx_set_environment(ngx_cycle_t *cycle, ngx_uint_t *last);
 ngx_pid_t ngx_exec_new_binary(ngx_cycle_t *cycle, char *const *argv);