diff --git a/setup.sh b/setup.sh
index e996d23..5cc791e 100644
--- a/setup.sh
+++ b/setup.sh
@@ -11,6 +11,8 @@ zfs_arch_dataset_name='archlinux'
 set -E
 trap '[ "$?" -ne 77 ] || exit 77' ERR
 
+declare zpool_drive
+
 function set_ntp () {
     timedatectl set-ntp true
 }