diff --git a/debian/part.btrfs.sh b/debian/part.btrfs.sh
index 02b292d..7ff1cdb 100755
--- a/debian/part.btrfs.sh
+++ b/debian/part.btrfs.sh
@@ -5,6 +5,9 @@
 #
 # Source: https://wiki.101010.fr/doku.php?id=debian:installation_btrfs
 
+# Ensure to run the script only with a btrfs root
+grep " /target btrfs " /etc/mtab || exit 1
+
 # Remount the partition with "compress" option
 mount -o remount,defaults,compress=lzo /target