diff --git a/debian/postinst b/debian/postinst
index 1870d16..da23440 100644
--- a/debian/postinst
+++ b/debian/postinst
@@ -28,7 +28,10 @@ touch /etc/vconsole.conf
 # Use the first crypttab entry as luks for booster (valid for calamares and probably most installers)
 if cat /etc/crypttab | grep -v '^#' | head -n1 | cut -f2 | grep -i "UUID="
 then
-  sed -i "s#root=#rd.luks.name="$(cat /etc/crypttab | grep -v '^#' | head -n1 | cut -f2 | sed "s#UUID=##")"="$(cat /etc/crypttab | grep -v '^#' | head -n1 | cut -f1)" root=#" /boot/refind_linux.conf
+  if cat /etc/crypttab | grep -i 'rd.luks'
+  then
+    sed -i "s#root=#rd.luks.name="$(cat /etc/crypttab | grep -v '^#' | head -n1 | cut -f2 | sed "s#UUID=##")"="$(cat /etc/crypttab | grep -v '^#' | head -n1 | cut -f1)" root=#" /boot/refind_linux.conf
+  fi
 else
   echo -e "ERROR 1: /etc/crypttab is invalid!\nFirst crypttab entry (presumed to be root luks) is not defined via UUID\nPlease make sure to define luks for root as the first entry in /etc/crypttab via UUID (use blkid)"
   exit 1