diff --git a/src/lib/monitor-worker.ts b/src/lib/monitor-worker.ts
index 7d8d3b3..0318617 100644
--- a/src/lib/monitor-worker.ts
+++ b/src/lib/monitor-worker.ts
@@ -146,7 +146,7 @@ export class MonitorWorker {
           id: ch.id as number,
           name: ch.name as string,
           webhookUrl: (raw.webhook_url as string) || '',
-          channelType: (raw.channel_type as string) || 'wechat',
+          channelType: ((raw.channel_type as string) || 'wechat') as 'wechat' | 'email',
           enabled: !!ch.enabled_num,
           levelCritical: !!ch.level_critical_num,
           levelWarning: !!ch.level_warning_num,