diff --git a/setup-nasbeery b/setup-nasbeery
index 3a0471d..c985a5d 100644
--- a/setup-nasbeery
+++ b/setup-nasbeery
@@ -141,12 +141,11 @@ modprobe zfs
 echo "Update time via ntp"
 ntpdate-debian -b > /dev/null
 
-rootfs=$(grep " / " /proc/mounts | cut -d'/' -f3)
-if [[ "$rootfs" == *"nvme"* ]] || [[ "$rootfs" == *"mmcblk"* ]]; then
-  rootdisk=${rootfs::-3}
-else
-  rootdisk=${rootfs::1}
-fi
+echo "Detecting root disk (SAFETY CHECK)"
+rootdisk=$(findmnt -n -o SOURCE / | sed 's/[0-9]*$//;s/p$//')
+rootdisk=$(basename "$rootdisk")
+
+echo "Root disk detected as: /dev/$rootdisk"
 
 zdisks=$(echo $(lsblk -nd -I 8,259,179 -o name | grep -v ${rootdisk}) | cut -d' ' -f1-2)
 case $FORMAT in