diff --git a/modules/story-summary/story-summary.js b/modules/story-summary/story-summary.js
index 30f29f9..b10ce21 100644
--- a/modules/story-summary/story-summary.js
+++ b/modules/story-summary/story-summary.js
@@ -615,7 +615,9 @@ async function handleClearVectors() {
     await clearEventVectors(chatId);
     await clearAllChunks(chatId);
     await clearStateVectors(chatId);
-    await updateMeta(chatId, { lastChunkFloor: -1 });
+    // Reset both boundary and fingerprint so next incremental build starts from floor 0
+    // without being blocked by stale engine fingerprint mismatch.
+    await updateMeta(chatId, { lastChunkFloor: -1, fingerprint: null });
     await sendVectorStatsToFrame();
     await executeSlashCommand('/echo severity=info 向量数据已清除。如需恢复召回功能，请重新点击"生成向量"。');
     xbLog.info(MODULE_ID, "向量数据已清除");