diff --git a/test/bdev/nbd_common.sh b/test/bdev/nbd_common.sh
index 0dffd94aa..fa3383f80 100644
--- a/test/bdev/nbd_common.sh
+++ b/test/bdev/nbd_common.sh
@@ -125,13 +125,15 @@ function nbd_rpc_start_stop_verify() {
 function nbd_with_lvol_verify() {
 	local rpc_server=$1
 	local nbd_list=($2)
+	local mkfs_ret
 
 	$rootdir/scripts/rpc.py -s $rpc_server bdev_malloc_create -b malloc_lvol_verify 16 512
 	$rootdir/scripts/rpc.py -s $rpc_server bdev_lvol_create_lvstore malloc_lvol_verify lvs
 	$rootdir/scripts/rpc.py -s $rpc_server bdev_lvol_create lvol 4 -l lvs
 	$rootdir/scripts/rpc.py -s $rpc_server nbd_start_disk lvs/lvol "${nbd_list[0]}"
 
-	mkfs_ret=$(mkfs.ext4 ${nbd_list[0]})
+	mkfs.ext4 ${nbd_list[0]}
+	mkfs_ret=$?
 	nbd_stop_disks $rpc_server "${nbd_list[0]}"
 	if [ $mkfs_ret -ne 0 ]; then
 		return 1