diff --git a/themes/hugo-book b/themes/hugo-book
index 7c78a39..9405c4c 160000
--- a/themes/hugo-book
+++ b/themes/hugo-book
@@ -1 +1 @@
-Subproject commit 7c78a39c531aa2492ed7e92f2ce9dfb2c8c0d3fa
+Subproject commit 9405c4c3d7c7d81ae5be06589982691efedac3ea