diff --git a/book/external/Nested-Books b/book/external/Nested-Books
index 31b500d..a17b284 160000
--- a/book/external/Nested-Books
+++ b/book/external/Nested-Books
@@ -1 +1 @@
-Subproject commit 31b500d8fafa88630095eb824fad2f89c8b9f04e
+Subproject commit a17b28450b0a15f7a353f99b0d99061ff4babecf