diff --git a/tools/boostbook b/tools/boostbook
index 322bd0adcc..c693753132 160000
--- a/tools/boostbook
+++ b/tools/boostbook
@@ -1 +1 @@
-Subproject commit 322bd0adccea20ff5fc6d20088f2e2704eb1fddc
+Subproject commit c693753132f71365a61640c8491eb56cb2a1ee68