diff --git a/drivers/mtd/mtdconcat.c b/drivers/mtd/mtdconcat.c
index 5060e608ea5d..e601672a5305 100644
--- a/drivers/mtd/mtdconcat.c
+++ b/drivers/mtd/mtdconcat.c
@@ -319,7 +319,7 @@ concat_write_oob(struct mtd_info *mtd, loff_t to, struct mtd_oob_ops *ops)
 	if (!(mtd->flags & MTD_WRITEABLE))
 		return -EROFS;
 
-	ops->retlen = 0;
+	ops->retlen = ops->oobretlen = 0;
 
 	for (i = 0; i < concat->num_subdev; i++) {
 		struct mtd_info *subdev = concat->subdev[i];
@@ -334,7 +334,7 @@ concat_write_oob(struct mtd_info *mtd, loff_t to, struct mtd_oob_ops *ops)
 			devops.len = subdev->size - to;
 
 		err = subdev->write_oob(subdev, to, &devops);
-		ops->retlen += devops.retlen;
+		ops->retlen += devops.oobretlen;
 		if (err)
 			return err;