diff --git a/install-grub.sh b/install-grub.sh
index 8af7285..af25d49 100644
--- a/install-grub.sh
+++ b/install-grub.sh
@@ -345,7 +345,7 @@ echo
 # Install bootloader.
 echo "Installing GRUB."
 arch-chroot /mnt grub-install --target=i386-pc /dev/$dev &&
-sed -i '7s|.*|GRUB_CMDLINE_LINUX="cryptdevice=/dev/$main:lvm root=/dev/mapper/main-root"|' /mnt/etc/default/grub &&
+sed -i '7s|.*|GRUB_CMDLINE_LINUX="cryptdevice=/dev/'$main':lvm root=/dev/mapper/main-root"|' /mnt/etc/default/grub &&
 sed -i '10s/.*/GRUB_PRELOAD_MODULES="part_gpt part_msdos lvm"/' /mnt/etc/default/grub &&
 arch-chroot /mnt grub-mkconfig -o /boot/grub/grub.cfg &&
 echo "Done."