diff --git a/drivers/staging/rts_pstor/ms.c b/drivers/staging/rts_pstor/ms.c
index 66341dff8c99..f9a4498984cc 100644
--- a/drivers/staging/rts_pstor/ms.c
+++ b/drivers/staging/rts_pstor/ms.c
@@ -3498,7 +3498,8 @@ static int ms_rw_multi_sector(struct scsi_cmnd *srb, struct rtsx_chip *chip, u32
 
 		log_blk++;
 
-		for (seg_no = 0; seg_no < sizeof(ms_start_idx)/2; seg_no++) {
+		for (seg_no = 0; seg_no < ARRAY_SIZE(ms_start_idx) - 1;
+				seg_no++) {
 			if (log_blk < ms_start_idx[seg_no+1])
 				break;
 		}