diff --git a/book/external/Nested-Books b/book/external/Nested-Books
index 887a1c5..8af34ee 160000
--- a/book/external/Nested-Books
+++ b/book/external/Nested-Books
@@ -1 +1 @@
-Subproject commit 887a1c5a4e9955555bb1437cf1b4e05861290572
+Subproject commit 8af34ee7b400a850c7539252fc4a257291de33d2