diff --git a/build-grub.sh b/build-grub.sh
index 2bdabf6..26e9022 100755
--- a/build-grub.sh
+++ b/build-grub.sh
@@ -39,6 +39,8 @@ grub-mkimage \
 echo 'Generating GRUB configuration file ...'
 mkdir -p "${O}"/efi-part/EFI/gentoo
 cp -uv grub.cfg "${O}"/efi-part/EFI/gentoo
-grub-editenv "${O}"/efi-part/EFI/gentoo/grubenv set rootflags='ro'
-grub-editenv "${O}"/efi-part/EFI/gentoo/grubenv set default=0
-grub-editenv "${O}"/efi-part/EFI/gentoo/grubenv set timeout=5
+grub-editenv "${O}"/efi-part/EFI/gentoo/grubenv set \
+    rootflags="${rootflags-ro}" \
+    default=0 \
+    timeout=5 \
+    && :