diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index b015e46..7503330 100644
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -54,7 +54,8 @@
 		| UBLK_F_USER_RECOVERY_REISSUE)
 
 /* All UBLK_PARAM_TYPE_* should be included here */
-#define UBLK_PARAM_TYPE_ALL (UBLK_PARAM_TYPE_BASIC | UBLK_PARAM_TYPE_DISCARD)
+#define UBLK_PARAM_TYPE_ALL (UBLK_PARAM_TYPE_BASIC | \
+		UBLK_PARAM_TYPE_DISCARD | UBLK_PARAM_TYPE_DEVT)
 
 struct ublk_rq_data {
 	struct llist_node node;
@@ -255,6 +256,10 @@ static int ublk_validate_params(const struct ublk_device *ub)
 			return -EINVAL;
 	}
 
+	/* dev_t is read-only */
+	if (ub->params.types & UBLK_PARAM_TYPE_DEVT)
+		return -EINVAL;
+
 	return 0;
 }
 
@@ -1777,6 +1782,22 @@ static int ublk_ctrl_get_dev_info(struct ublk_device *ub,
 	return 0;
 }
 
+/* TYPE_DEVT is readonly, so fill it up before returning to userspace */
+static void ublk_ctrl_fill_params_devt(struct ublk_device *ub)
+{
+	ub->params.devt.char_major = MAJOR(ub->cdev_dev.devt);
+	ub->params.devt.char_minor = MINOR(ub->cdev_dev.devt);
+
+	if (ub->ub_disk) {
+		ub->params.devt.disk_major = MAJOR(disk_devt(ub->ub_disk));
+		ub->params.devt.disk_minor = MINOR(disk_devt(ub->ub_disk));
+	} else {
+		ub->params.devt.disk_major = 0;
+		ub->params.devt.disk_minor = 0;
+	}
+	ub->params.types |= UBLK_PARAM_TYPE_DEVT;
+}
+
 static int ublk_ctrl_get_params(struct ublk_device *ub,
 		struct io_uring_cmd *cmd)
 {
@@ -1798,6 +1819,7 @@ static int ublk_ctrl_get_params(struct ublk_device *ub,
 		ph.len = sizeof(struct ublk_params);
 
 	mutex_lock(&ub->mutex);
+	ublk_ctrl_fill_params_devt(ub);
 	if (copy_to_user(argp, &ub->params, ph.len))
 		ret = -EFAULT;
 	else