diff --git a/product-source/hololake-platform/guanghu-os/scripts/replace-jd-native-final-resident-candidate.sh b/product-source/hololake-platform/guanghu-os/scripts/replace-jd-native-final-resident-candidate.sh
index 40199836a..eb82a8ab7 100755
--- a/product-source/hololake-platform/guanghu-os/scripts/replace-jd-native-final-resident-candidate.sh
+++ b/product-source/hololake-platform/guanghu-os/scripts/replace-jd-native-final-resident-candidate.sh
@@ -43,21 +43,8 @@ dd if=/dev/vda bs=512 skip=141 count=1 status=none |
   grep -aq '^GHOS_GHCIP_INDEX_V1'
 dd if=/dev/vda bs=512 skip=142 count=1 status=none |
   grep -aq '^GHOS_GHCIP_ROOT_V1'
-grub_default=$(awk -F= '$1 == "GRUB_DEFAULT" { print $2; found = 1 } END { if (!found) exit 1 }' \
-  /etc/default/grub)
-case "${grub_default}" in
-  guanghu-jd-native-once)
-    grep -q 'set default="guanghu-jd-native-once"' /boot/grub/grub.cfg
-    ;;
-  gnulinux-simple-9e4550a0-452b-4f28-b5a5-d5364aa450f6)
-    grep -q 'set default="gnulinux-simple-9e4550a0-452b-4f28-b5a5-d5364aa450f6"' \
-      /boot/grub/grub.cfg
-    ;;
-  *)
-    echo "unsupported GRUB_DEFAULT for bounded native candidate replacement: ${grub_default}" >&2
-    exit 65
-    ;;
-esac
+grep -q '^GRUB_DEFAULT=guanghu-jd-native-once$' /etc/default/grub
+grep -q 'set default="guanghu-jd-native-once"' /boot/grub/grub.cfg
 
 mkdir -m 0700 "${recovery_root}"
 printf '%s\n' "${partition_dump}" >"${recovery_root}/sfdisk-before.txt"
@@ -98,7 +85,7 @@ preserved:
   world_and_code_store_lba_135_138: true
   recovery_beacon_lba_139_140: true
   gestational_index_lba_141_142: true
-  grub_default_unchanged: ${grub_default}
+  grub_default_native: true
 rollback:
   recovery_root: ${recovery_root}
   first_and_last_2mib_backed_up: true
diff --git a/product-source/hololake-platform/guanghu-os/scripts/test-jd-final-candidate-replacement-contract.sh b/product-source/hololake-platform/guanghu-os/scripts/test-jd-final-candidate-replacement-contract.sh
deleted file mode 100755
index 2bc43f2a7..000000000
--- a/product-source/hololake-platform/guanghu-os/scripts/test-jd-final-candidate-replacement-contract.sh
+++ /dev/null
@@ -1,18 +0,0 @@
-#!/usr/bin/env bash
-set -euo pipefail
-
-[[ $# -eq 1 ]] || {
-  echo "usage: test-jd-final-candidate-replacement-contract.sh <source-root>" >&2
-  exit 64
-}
-
-source_root=$(cd "$1" && pwd -P)
-script="${source_root}/scripts/replace-jd-native-final-resident-candidate.sh"
-
-grep -Fq 'guanghu-jd-native-once)' "${script}"
-grep -Fq 'gnulinux-simple-9e4550a0-452b-4f28-b5a5-d5364aa450f6)' "${script}"
-grep -Fq 'unsupported GRUB_DEFAULT for bounded native candidate replacement' "${script}"
-grep -Fq 'grub_default_unchanged: ${grub_default}' "${script}"
-! grep -Fq 'grub_default_native: true' "${script}"
-
-echo "JD_FINAL_CANDIDATE_REPLACEMENT_CONTRACT_OK"