diff --git a/drivers/mtd/ubi/fastmap.c b/drivers/mtd/ubi/fastmap.c
index f683d422e..d94e1d964 100644
--- a/drivers/mtd/ubi/fastmap.c
+++ b/drivers/mtd/ubi/fastmap.c
@@ -1458,8 +1458,10 @@ err:
 	ret = 0;
 	if (old_fm) {
 		ret = invalidate_fastmap(ubi, old_fm);
-		if (ret < 0)
+		if (ret < 0) {
 			ubi_err(ubi, "Unable to invalidiate current fastmap!");
+			ubi_ro_mode(ubi);
+		}
 		else if (ret)
 			ret = 0;
 	}