diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index b274fdf..c837507 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -695,6 +695,7 @@
 		return -EINVAL;
 	if (!(mtd->flags & MTD_WRITEABLE))
 		return -EROFS;
+	instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
 	if (!instr->len) {
 		instr->state = MTD_ERASE_DONE;
 		mtd_erase_callback(instr);