diff --git a/commands/ubi.c b/commands/ubi.c
index 94da799b8..218eda083 100644
--- a/commands/ubi.c
+++ b/commands/ubi.c
@@ -8,6 +8,7 @@
 #include <linux/mtd/mtd.h>
 #include <linux/kernel.h>
 #include <linux/mtd/mtd-abi.h>
+#include <linux/err.h>
 #include <mtd/ubi-user.h>
 #include <mtd/ubi-media.h>
 
@@ -58,14 +59,37 @@ BAREBOX_CMD_START(ubimkvol)
 	BAREBOX_CMD_HELP(cmd_ubimkvol_help)
 BAREBOX_CMD_END
 
+static struct mtd_info *get_mtd_info(const char *path)
+{
+	int fd;
+	struct mtd_info_user user;
+	int ret;
+
+	fd = open(path, O_RDWR);
+	if (fd < 0) {
+		perror("open");
+		return ERR_PTR(fd);
+	}
+
+	ret = ioctl(fd, MEMGETINFO, &user);
+
+	close(fd);
+
+	if (ret) {
+		printf("MEMGETINFO failed: %s\n", strerror(-ret));
+		return ERR_PTR(ret);
+	}
+
+	return user.mtd;
+}
 
 static int do_ubiattach(int argc, char *argv[])
 {
 	int opt;
-	struct mtd_info_user user;
-	int fd, ret;
+	int ret;
 	int vid_hdr_offset = 0;
 	int devnum = UBI_DEV_NUM_AUTO;
+	struct mtd_info *mtd;
 
 	while((opt = getopt(argc, argv, "d:O:")) > 0) {
 		switch(opt) {
@@ -83,25 +107,15 @@ static int do_ubiattach(int argc, char *argv[])
 	if (optind == argc)
 		return COMMAND_ERROR_USAGE;
 
-	fd = open(argv[optind], O_RDWR);
-	if (fd < 0) {
-		perror("open");
-		return 1;
-	}
+	mtd = get_mtd_info(argv[optind]);
+	if (IS_ERR(mtd))
+		return PTR_ERR(mtd);
 
-	ret = ioctl(fd, MEMGETINFO, &user);
-	if (ret) {
-		printf("MEMGETINFO failed: %s\n", strerror(-ret));
-		goto err;
-	}
-
-	ret = ubi_attach_mtd_dev(user.mtd, devnum, vid_hdr_offset, 20);
+	ret = ubi_attach_mtd_dev(mtd, devnum, vid_hdr_offset, 20);
 	if (ret < 0)
 		printf("failed to attach: %s\n", strerror(-ret));
 	else
 		ret = 0;
-err:
-	close(fd);
 
 	return ret ? 1 : 0;
 }
@@ -122,13 +136,17 @@ BAREBOX_CMD_END
 
 static int do_ubidetach(int argc, char *argv[])
 {
-	int ubi_num, ret;
+	int ret;
+	struct mtd_info *mtd;
 
 	if (argc != 2)
 		return COMMAND_ERROR_USAGE;
 
-	ubi_num = simple_strtoul(argv[1], NULL, 0);
-	ret = ubi_detach_mtd_dev(ubi_num, 1);
+	mtd = get_mtd_info(argv[1]);
+	if (IS_ERR(mtd))
+		return PTR_ERR(mtd);
+
+	ret = ubi_detach_mtd_dev(mtd, 1);
 
 	if (ret)
 		printf("failed to detach: %s\n", strerror(-ret));
@@ -138,8 +156,8 @@ static int do_ubidetach(int argc, char *argv[])
 
 BAREBOX_CMD_START(ubidetach)
 	.cmd		= do_ubidetach,
-	BAREBOX_CMD_DESC("detach an UBI device")
-	BAREBOX_CMD_OPTS("UBINUM")
+	BAREBOX_CMD_DESC("detach mtd device from UBI")
+	BAREBOX_CMD_OPTS("UBIDEV")
 	BAREBOX_CMD_GROUP(CMD_GRP_PART)
 BAREBOX_CMD_END
 
diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c
index b02880eb7..396497bdc 100644
--- a/drivers/mtd/ubi/build.c
+++ b/drivers/mtd/ubi/build.c
@@ -683,6 +683,20 @@ out_free:
 	return err;
 }
 
+static struct ubi_device *ubi_find_mtd(struct mtd_info *mtd)
+{
+	struct ubi_device *ubi;
+	int i;
+
+	for (i = 0; i < UBI_MAX_DEVICES; i++) {
+		ubi = ubi_devices[i];
+		if (ubi && ubi->mtd == mtd)
+			return ubi;
+	}
+
+	return NULL;
+}
+
 /**
  * ubi_detach_mtd_dev - detach an MTD device.
  * @ubi_num: UBI device number to detach from
@@ -696,13 +710,17 @@ out_free:
  * Note, the invocations of this function has to be serialized by the
  * @ubi_devices_mutex.
  */
-int ubi_detach_mtd_dev(int ubi_num, int anyway)
+int ubi_detach_mtd_dev(struct mtd_info *mtd, int anyway)
 {
 	struct ubi_device *ubi;
+	int ubi_num;
 
-	if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
+	ubi = ubi_find_mtd(mtd);
+	if (!ubi)
 		return -EINVAL;
 
+	ubi_num = ubi->ubi_num;
+
 	ubi = ubi_get_device(ubi_num);
 	if (!ubi)
 		return -EINVAL;
diff --git a/include/mtd/ubi-user.h b/include/mtd/ubi-user.h
index 2000ef2fd..14f309afd 100644
--- a/include/mtd/ubi-user.h
+++ b/include/mtd/ubi-user.h
@@ -406,6 +406,6 @@ struct ubi_set_vol_prop_req {
 
 int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num,
 		       int vid_hdr_offset, int max_beb_per1024);
-int ubi_detach_mtd_dev(int ubi_num, int anyway);
+int ubi_detach_mtd_dev(struct mtd_info *mtd, int anyway);
 
 #endif /* __UBI_USER_H__ */