diff --git a/tools/boostbook b/tools/boostbook
index 413f3e016d..2f9b23ea4d 160000
--- a/tools/boostbook
+++ b/tools/boostbook
@@ -1 +1 @@
-Subproject commit 413f3e016d1ae9fecdda6bfb48734ea05d5615a6
+Subproject commit 2f9b23ea4de479518781b59b4f57cd480e4308c0