diff --git a/src/os/unix/ngx_files.h b/src/os/unix/ngx_files.h
index c4eccf1fe..d4ad8a467 100644
--- a/src/os/unix/ngx_files.h
+++ b/src/os/unix/ngx_files.h
@@ -55,7 +55,12 @@ ssize_t ngx_write_chain_to_file(ngx_file_t *file, ngx_chain_t *ce,
     off_t offset, ngx_pool_t *pool);
 
 
+#define ngx_read_fd              read
+#define ngx_read_fd_n            "read()"
+
 #define ngx_write_fd             write
+#define ngx_write_fd_n           "write()"
+
 #define ngx_linefeed(p)          *p++ = LF;
 #define NGX_LINEFEED_SIZE        1
 
diff --git a/src/os/win32/ngx_files.h b/src/os/win32/ngx_files.h
index f5a97f8b4..96e0c8d44 100644
--- a/src/os/win32/ngx_files.h
+++ b/src/os/win32/ngx_files.h
@@ -68,7 +68,12 @@ ngx_int_t ngx_file_append_mode(ngx_fd_t fd);
 #define ngx_close_file_n            "CloseHandle()"
 
 
+#define ngx_read_fd(fd, buf, size)  ReadFile(fd, buf, size, NULL, NULL)
+#define ngx_read_fd_n               "ReadFile()"
+
 #define ngx_write_fd(fd, buf, size) WriteFile(fd, buf, size, NULL, NULL)
+#define ngx_write_fd_n              "WriteFile()"
+
 #define ngx_linefeed(p)             *p++ = CR; *p++ = LF;
 #define NGX_LINEFEED_SIZE           2