diff --git a/frontend/src/startup.ts b/frontend/src/startup.ts
index b0ea34c..a602afb 100644
--- a/frontend/src/startup.ts
+++ b/frontend/src/startup.ts
@@ -1,4 +1,4 @@
-import commonStore from './stores/commonStore';
+import commonStore, { Platform } from './stores/commonStore';
 import { GetPlatform, ReadJson } from '../wailsjs/go/backend_golang/App';
 import { Cache, checkUpdate, downloadProgramFiles, LocalConfig, refreshModels } from './utils';
 import { getStatus } from './apis';
@@ -15,7 +15,7 @@ export async function startup() {
 
   initCache().then(initRemoteText);
 
-  await GetPlatform().then(p => commonStore.setPlatform(p));
+  await GetPlatform().then(p => commonStore.setPlatform(p as Platform));
   await initConfig();
 
   if (commonStore.settings.autoUpdatesCheck) // depends on config settings
diff --git a/frontend/src/stores/commonStore.ts b/frontend/src/stores/commonStore.ts
index 441f197..abed62a 100644
--- a/frontend/src/stores/commonStore.ts
+++ b/frontend/src/stores/commonStore.ts
@@ -25,6 +25,8 @@ export type Status = {
   device_name: string;
 }
 
+export type Platform = 'windows' | 'darwin' | 'linux';
+
 class CommonStore {
   // global
   status: Status = {
@@ -33,7 +35,7 @@ class CommonStore {
     device_name: 'CPU'
   };
   depComplete: boolean = false;
-  platform: string = 'windows';
+  platform: Platform = 'windows';
   // home
   introduction: IntroductionContent = manifest.introduction;
   // chat
@@ -170,7 +172,7 @@ class CommonStore {
     this.completionGenerating = value;
   }
 
-  setPlatform(value: string) {
+  setPlatform(value: Platform) {
     this.platform = value;
   }
 }