diff --git a/src/telegram/bot-message-context.ts b/src/telegram/bot-message-context.ts
index 9c4db19b6..c09da0774 100644
--- a/src/telegram/bot-message-context.ts
+++ b/src/telegram/bot-message-context.ts
@@ -637,6 +637,8 @@ export const buildTelegramMessageContext = async ({
           channel: "telegram",
           to: String(chatId),
           accountId: route.accountId,
+          // Preserve DM topic threadId for replies (fixes #8891)
+          threadId: dmThreadId != null ? String(dmThreadId) : undefined,
         }
       : undefined,
     onRecordError: (err) => {