diff --git a/packages/hydrooj/package.json b/packages/hydrooj/package.json
index b094edf9f..f0cc60c8d 100644
--- a/packages/hydrooj/package.json
+++ b/packages/hydrooj/package.json
@@ -1,6 +1,6 @@
 {
     "name": "hydrooj",
-    "version": "2.28.29",
+    "version": "2.28.30",
     "bin": "bin/hydrooj.js",
     "main": "dist/loader.js",
     "typings": "dist/loader.d.ts",
diff --git a/packages/hydrooj/src/handler/problem.ts b/packages/hydrooj/src/handler/problem.ts
index 76be80a1b..cf3bf20de 100644
--- a/packages/hydrooj/src/handler/problem.ts
+++ b/packages/hydrooj/src/handler/problem.ts
@@ -29,7 +29,7 @@ import {
 } from '../service/server';
 
 export const parseCategory = (value: string) => flatten(value.split('+').map((e) => e.split(','))).map((e) => e.trim());
-export const parsePid = (value: string) => (isSafeInteger(value) ? parseInt(value, 10) : value);
+export const parsePid = (value: string) => (isSafeInteger(value) ? +value : value);
 
 export class ProblemHandler extends Handler {
     async cleanup() {
diff --git a/packages/hydrooj/src/model/record.ts b/packages/hydrooj/src/model/record.ts
index 1273b0543..221dc03dd 100644
--- a/packages/hydrooj/src/model/record.ts
+++ b/packages/hydrooj/src/model/record.ts
@@ -211,7 +211,7 @@ class RecordModel {
         }
         if (!contestInfo) {
             return RecordModel.coll.find({
-                domainId, uid, pdomain, pid, contest: { $exists: false },
+                domainId, uid, pdomain, pid, contest: null,
             });
         }
         return RecordModel.coll.find({