diff --git a/external/book b/external/book
index 2b81d844673c1ba09fd596d70492375f2998ad36..fe1df41a7f45a02f5c36a5dc55053b6ba04bafa0 160000
--- a/external/book
+++ b/external/book
@@ -1 +1 @@
-Subproject commit 2b81d844673c1ba09fd596d70492375f2998ad36
+Subproject commit fe1df41a7f45a02f5c36a5dc55053b6ba04bafa0