diff --git a/book/external/Nested-Books b/book/external/Nested-Books
index 587accb..51f0ba6 160000
--- a/book/external/Nested-Books
+++ b/book/external/Nested-Books
@@ -1 +1 @@
-Subproject commit 587accb350eae83cf7521a2fad5d18d6cb127698
+Subproject commit 51f0ba6754f0a5f95032e09482a7a28145687624