diff --git a/packages/hydrojudge/src/checkers.ts b/packages/hydrojudge/src/checkers.ts
index 10037e41c..e2fdabb27 100644
--- a/packages/hydrojudge/src/checkers.ts
+++ b/packages/hydrojudge/src/checkers.ts
@@ -1,5 +1,4 @@
 /* eslint-disable no-template-curly-in-string */
-import fs from 'fs-extra';
 import * as STATUS from './status';
 import { parse } from './testlib';
 import { run } from './sandbox';
diff --git a/packages/ui-default/components/monaco/index.js b/packages/ui-default/components/monaco/index.js
index 426707a82..34c9a1133 100644
--- a/packages/ui-default/components/monaco/index.js
+++ b/packages/ui-default/components/monaco/index.js
@@ -58,7 +58,7 @@ const problemConfigSchema = {
     subType: { type: 'string' },
     langs: { type: 'array', items: { type: 'string' } },
     target: { type: 'string' },
-    checker_type: { enum: ['default', 'lemon', 'syzoj', 'testlib', 'strict', 'qduoj'] },
+    checker_type: { enum: ['default', 'lemon', 'syzoj', 'hustoj', 'testlib', 'strict', 'qduoj'] },
     checker: { type: 'string', pattern: '\\.' },
     interactor: { type: 'string', pattern: '\\.' },
     user_extra_files: { type: 'array', items: { type: 'string' } },
diff --git a/packages/ui-default/package.json b/packages/ui-default/package.json
index ddea002c2..1af7caae6 100644
--- a/packages/ui-default/package.json
+++ b/packages/ui-default/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@hydrooj/ui-default",
-  "version": "4.15.1",
+  "version": "4.15.2",
   "author": "undefined <i@undefined.moe>",
   "license": "AGPL-3.0",
   "main": "hydro.js",
@@ -113,6 +113,7 @@
     "webpackbar": "^5.0.0-3"
   },
   "dependencies": {
+    "clean-webpack-plugin": "^4.0.0-alpha.0",
     "esbuild": "^0.12.18",
     "esbuild-loader": "^2.14.0",
     "js-yaml": "^4.1.0",