diff --git a/drivers/mtd/core.c b/drivers/mtd/core.c
index ae7818a..15fe9ce 100644
--- a/drivers/mtd/core.c
+++ b/drivers/mtd/core.c
@@ -589,11 +589,8 @@
 			continue;
 
 		filetype = file_detect_type(buf, bufsize);
-		if (filetype == filetype_ubi) {
+		if (filetype == filetype_ubi && ubi_num_get_by_mtd(mtd) < 0)
 			ret = ubi_attach_mtd_dev(mtd, UBI_DEV_NUM_AUTO, 0, 20);
-			if (ret == -EEXIST)
-				ret = 0;
-		}
 
 		break;
 	}