diff --git a/src/modules/rag-chat/rag-chat.service.ts b/src/modules/rag-chat/rag-chat.service.ts
index 43bf2f8..742f83d 100644
--- a/src/modules/rag-chat/rag-chat.service.ts
+++ b/src/modules/rag-chat/rag-chat.service.ts
@@ -1,4 +1,4 @@
-import { Injectable, NotFoundException, Logger } from '@nestjs/common';
+import { Injectable, NotFoundException, Logger, Optional } from '@nestjs/common';
 import { PrismaService } from '../../infrastructure/database/prisma.service';
 import { ContentSafetyService } from '../content-safety/content-safety.service';
 
@@ -8,7 +8,7 @@ export class RagChatService {
 
   constructor(
     private readonly prisma: PrismaService,
-    private readonly safety?: ContentSafetyService,
+    @Optional() private readonly safety?: ContentSafetyService,
   ) {}
 
   async createSession(userId: string, knowledgeBaseId: string, title?: string) {