--- a/src/core/ngx_core.h
+++ b/src/core/ngx_core.h
@@ -5,11 +5,11 @@
 typedef struct ngx_module_s      ngx_module_t;
 typedef struct ngx_conf_s        ngx_conf_t;
 typedef struct ngx_cycle_s       ngx_cycle_t;
+typedef struct ngx_pool_s        ngx_pool_t;
 typedef struct ngx_log_s         ngx_log_t;
 typedef struct ngx_array_s       ngx_array_t;
 typedef struct ngx_open_file_s   ngx_open_file_t;
 typedef struct ngx_command_s     ngx_command_t;
-
 typedef struct ngx_file_s        ngx_file_t;
 typedef struct ngx_event_s       ngx_event_t;
 typedef struct ngx_connection_s  ngx_connection_t;