diff --git a/book/external/Nested-Books b/book/external/Nested-Books
index 0660e78..f063877 160000
--- a/book/external/Nested-Books
+++ b/book/external/Nested-Books
@@ -1 +1 @@
-Subproject commit 0660e7846161be8e1aec42321af727680b851179
+Subproject commit f063877cc9efa7bd1d14eab0cba71f50e4aeb957