diff --git a/src/doc/book b/src/doc/book
index 194eb8d5f175..a645960fe489 160000
--- a/src/doc/book
+++ b/src/doc/book
@@ -1 +1 @@
-Subproject commit 194eb8d5f1753fb5f4501011cebdc1b585712474
+Subproject commit a645960fe48946153936dd5628df4a90bd837981