diff --git a/script/lib.sh b/script/lib.sh
index 895f331..c9c207e 100644
--- a/script/lib.sh
+++ b/script/lib.sh
@@ -158,6 +158,7 @@ function pre_install() {
 			# Zap existing partition table
 			echo "...Erasing partition table of \"${DEV}\"."
 			dd if=/dev/zero of="${DEV}" bs=512 count=1
+			if is_error ; then return 1 ; fi; 	# If error, terminate
 			# Create MBR and allocate max storage for Linux partition
 			echo "...Creating a Linux partition on ${DEV} with MBR."
 			sfdisk "${DEV}" <<- HEREDOC
diff --git a/script/void-kaiten-yaki.sh b/script/void-kaiten-yaki.sh
index 6dd8da4..87cfcd4 100644
--- a/script/void-kaiten-yaki.sh
+++ b/script/void-kaiten-yaki.sh
@@ -56,8 +56,8 @@ function main() {
 	# Common part of the pre-install stage
 	if ! pre_install ; then
 		# If error, restore the modification.
-		echo "...restoring modified /etc/default/grub."
-		sed -i -e "s#loglevel=4 ${GRUB_ADDITIONAL_PARAMETERS}#loglevel=4#" /etc/default/grub
+		echo "...restoring /etc/default/grub, if needed"
+		sed -i -e "s#${GRUB_ADDITIONAL_PARAMETERS}##" /etc/default/grub
 		return 1 # with error status
 	fi