diff --git a/packages/hydrooj/src/service/bus.ts b/packages/hydrooj/src/service/bus.ts
index 994ea8256..0e1f83719 100644
--- a/packages/hydrooj/src/service/bus.ts
+++ b/packages/hydrooj/src/service/bus.ts
@@ -1,5 +1,5 @@
 /* eslint-disable no-await-in-loop */
-import cluster from 'cluster';
+import cluster, { Worker } from 'cluster';
 import serialize from 'serialize-javascript';
 import cac from 'cac';
 import type {
@@ -195,7 +195,7 @@ export function boardcast<K extends keyof EventMap>(event: K, ...payload: Parame
     } else parallel(event, ...payload);
 }
 
-async function messageHandler(worker: cluster.Worker, msg: any) {
+async function messageHandler(worker: Worker, msg: any) {
     if (!msg) msg = worker;
     // eslint-disable-next-line no-eval
     if (typeof msg.payload === 'string') msg.payload = eval(msg.payload);