diff --git a/AIStudyApp/AIStudyApp/Features/AI/AIChatViewModel.swift b/AIStudyApp/AIStudyApp/Features/AI/AIChatViewModel.swift
index 38f06fb..adf3a83 100644
--- a/AIStudyApp/AIStudyApp/Features/AI/AIChatViewModel.swift
+++ b/AIStudyApp/AIStudyApp/Features/AI/AIChatViewModel.swift
@@ -55,7 +55,7 @@ final class AIChatViewModel: ObservableObject {
         do {
             let session = try await RagChatService.shared.createSession(knowledgeBaseId: kbId, title: nil)
             sessionId = session.id
-            messages = [AIMessage(role: .ai, content: "你好！我是你的 AI 学习助手，基于你的知识库回答问题。")]
+            messages = [AIMessage(role: .ai, content: "你好！我是你的 AI 学习助手，基于你的知识库回答问题。", citations: nil)]
             isCreatingSession = false
         } catch {
             sessionError = "创建对话失败"
@@ -79,7 +79,7 @@ final class AIChatViewModel: ObservableObject {
                     messages.append(AIMessage(role: .ai, content: resp.content ?? "抱歉，AI 暂时无法回复", citations: resp.citations))
                 }
             } catch {
-                messages.append(AIMessage(role: .ai, content: "发送失败: \(error.localizedDescription)"))
+                messages.append(AIMessage(role: .ai, content: "发送失败: \(error.localizedDescription)", citations: nil))
             }
             isSending = false
         }