diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c
index e85b04e9716b21523155864eed7b331651da9178..40fa994ad6a8f23207f7e2bd4f22365fe3c5713c 100644
--- a/drivers/mtd/ubi/build.c
+++ b/drivers/mtd/ubi/build.c
@@ -50,6 +50,7 @@
  * struct mtd_dev_param - MTD device parameter description data structure.
  * @name: MTD character device node path, MTD device name, or MTD device number
  *        string
+ * @ubi_num: UBI number
  * @vid_hdr_offs: VID header offset
  * @max_beb_per1024: maximum expected number of bad PEBs per 1024 PEBs
  */