diff --git a/mini-lsm-book/src/SUMMARY.md b/mini-lsm-book/src/SUMMARY.md
index f212232..b3c8268 100644
--- a/mini-lsm-book/src/SUMMARY.md
+++ b/mini-lsm-book/src/SUMMARY.md
@@ -34,7 +34,7 @@
 
 ---
 
-# Mini-LSM v1
+# DEPRECATED Mini-LSM v1
 
 - [Overview](./00-v1.md)
   - [Store key-value pairs in little blocks](./01-block.md)