diff --git a/packages/loro-websocket/src/server/simple-server.ts b/packages/loro-websocket/src/server/simple-server.ts
index 767142a..4a7c619 100644
--- a/packages/loro-websocket/src/server/simple-server.ts
+++ b/packages/loro-websocket/src/server/simple-server.ts
@@ -94,7 +94,14 @@ export class SimpleServer {
 
   start(): Promise<void> {
     return new Promise(resolve => {
-      const options: { port: number; host?: string; verifyClient?: any } = {
+      const options: {
+        port: number;
+        host?: string;
+        verifyClient?: (
+          info: { origin: string; secure: boolean; req: IncomingMessage },
+          cb: (res: boolean, code?: number, message?: string) => void
+        ) => void;
+      } = {
         port: this.config.port,
       };
       if (this.config.host) {
diff --git a/packages/loro-websocket/tests/handshake-auth.test.ts b/packages/loro-websocket/tests/handshake-auth.test.ts
index 910857d..1cbbbce 100644
--- a/packages/loro-websocket/tests/handshake-auth.test.ts
+++ b/packages/loro-websocket/tests/handshake-auth.test.ts
@@ -1,4 +1,4 @@
-import { describe, it, expect, beforeAll, afterAll } from "vitest";
+import { describe, it, beforeAll, afterAll } from "vitest";
 import { WebSocket } from "ws";
 import getPort from "get-port";
 import { SimpleServer } from "../src/server/simple-server";
@@ -38,8 +38,12 @@ describe("Handshake Auth", () => {
     });
 
     await new Promise<void>((resolve, reject) => {
-      ws.onopen = () => resolve();
-      ws.onerror = err => reject(err);
+      ws.addEventListener("open", () => {
+        resolve();
+      });
+      ws.addEventListener("error", err => {
+        reject(err);
+      });
     });
     ws.close();
   });
@@ -52,10 +56,12 @@ describe("Handshake Auth", () => {
     });
 
     await new Promise<void>((resolve, reject) => {
-      ws.onopen = () => reject(new Error("Should have failed"));
-      ws.onerror = err => {
+      ws.addEventListener("open", () => {
+        reject(new Error("Should have failed"));
+      });
+      ws.addEventListener("error", () => {
         resolve();
-      };
+      });
     });
   });
 
@@ -63,8 +69,12 @@ describe("Handshake Auth", () => {
     const ws = new WebSocket(`ws://localhost:${port}`);
 
     await new Promise<void>((resolve, reject) => {
-      ws.onopen = () => reject(new Error("Should have failed"));
-      ws.onerror = () => resolve();
+      ws.addEventListener("open", () => {
+        reject(new Error("Should have failed"));
+      });
+      ws.addEventListener("error", () => {
+        resolve();
+      });
     });
   });
 });