diff --git a/tools/boostbook b/tools/boostbook
index a6701f5d27..53b9e5fe04 160000
--- a/tools/boostbook
+++ b/tools/boostbook
@@ -1 +1 @@
-Subproject commit a6701f5d278daba797697a1e5000ee41f25bcaff
+Subproject commit 53b9e5fe04eae6979aecfc26d4a911941689d7d6