diff --git a/src/os/unix/ngx_files.h b/src/os/unix/ngx_files.h
index 1526f9b..d397c2f 100644
--- a/src/os/unix/ngx_files.h
+++ b/src/os/unix/ngx_files.h
@@ -340,6 +340,8 @@
 
 #define ngx_file_at_info_n       "fstatat()"
 
+#define NGX_AT_FDCWD             (ngx_fd_t) AT_FDCWD
+
 #endif