diff --git a/scripts/prepare-update-repository.py b/scripts/prepare-update-repository.py
index 741866b..aeae4d5 100644
--- a/scripts/prepare-update-repository.py
+++ b/scripts/prepare-update-repository.py
@@ -44,7 +44,15 @@ allowed = {'scripts/init-security-env.sh'}
 if any(p not in allowed and not (Path(p).parent == Path('.') and p.endswith('.conf')) for p in collisions):
     sys.exit('❌ 存在新版仓库会覆盖的其他本地文件；尚未修改配置或容器')
 if not changed and not collisions:
-    sys.exit(0)
+    existing_override_path = root / 'data/deployment-config/legacy-compose.json'
+    restore_existing_pin = False
+    if restore_images and existing_override_path.exists():
+        if existing_override_path.is_symlink() or not existing_override_path.is_file():
+            sys.exit('❌ 旧配置覆盖文件类型不受支持；尚未修改配置或容器')
+        existing_override = json.loads(existing_override_path.read_text())
+        restore_existing_pin = any('image' in existing_override.get('services', {}).get(service, {}) for service in restore_images)
+    if not restore_existing_pin:
+        sys.exit(0)
 for name in changed | collisions:
     if not (root / name).is_file() or (root / name).is_symlink():
         sys.exit('❌ 配置文件类型不受支持；尚未修改配置或容器')
diff --git a/scripts/test-repository-image-restore.py b/scripts/test-repository-image-restore.py
index d349a5e..858645d 100644
--- a/scripts/test-repository-image-restore.py
+++ b/scripts/test-repository-image-restore.py
@@ -102,6 +102,18 @@ for restore in ('', 'easyai-web', 'redis', 'ws-gateway'):
         newest = max(backups, key=lambda p: p.stat().st_mtime)
         assert (newest / 'data/deployment-config/legacy-compose.json').read_bytes() == previous_override
         assert (newest / 'data/deployment-config/legacy-compose.json').stat().st_mode & 0o077 == 0
+        if not restore:
+            # Main is clean, but an existing override still pins the web image.
+            # Explicit restoration must act on that override and be idempotent.
+            restoration_env = {**env, 'UPDATE_RESTORE_REPOSITORY_IMAGES': 'easyai-web'}
+            checked(['python3', str(prepare), str(root)], root, restoration_env)
+            config = json.loads(checked(['docker', 'compose', '--env-file', '.env', 'config', '--format', 'json'], root))
+            assert config['services']['easyai-web']['image'] == 'repository-web:latest'
+            assert config['services']['redis']['image'] == 'redis:6.2'
+            assert config['services']['easyai-server']['environment']['LOCAL_SETTING'] == 'second-custom'
+            assert len(list((root / 'data/deployment-backups').glob('legacy-update-*'))) == 3
+            checked(['python3', str(prepare), str(root)], root, restoration_env)
+            assert len(list((root / 'data/deployment-backups').glob('legacy-update-*'))) == 3
 
 for mode, adopt in (('image', '1'), ('full', '0')):
     env = {**os.environ, 'UPDATE_MODE': mode, 'UPDATE_ADOPT_LEGACY_CONFIG': adopt, 'UPDATE_RESTORE_REPOSITORY_IMAGES': 'easyai-web'}