diff --git a/pibackup.sh b/pibackup.sh
index 5d3cf8f..881c181 100755
--- a/pibackup.sh
+++ b/pibackup.sh
@@ -11,11 +11,11 @@ Password="P1backup"
 
 logfile=/opt/idssys/pibackup/logfile
 
-if		[ -f /dev/nvme0n1 ];	then dtype=/dev/nvme0n1
-elif	[ -f /dev/mmcblk0 ];	then dtype=/dev/mmcblk0
+if grep '/dev/nvme0n1' /etc/mtab > /dev/null 2>&1; then dtype=/dev/nvme0n1
+elif grep '/dev/mmcblk0' /etc/mtab > /dev/null 2>&1; then dtype=/dev/mmcblk0
 fi
 
-echo "HERE: ${dtype}"
+echo "HERE: $dtype"
 
 # BackupDir="${MountPoint}/${hostname}"
 #