diff --git a/themes/hugo-book b/themes/hugo-book
index e104a11f42fbd069aa15606c5f01631b07d7528c..7c78a39c531aa2492ed7e92f2ce9dfb2c8c0d3fa 160000
--- a/themes/hugo-book
+++ b/themes/hugo-book
@@ -1 +1 @@
-Subproject commit e104a11f42fbd069aa15606c5f01631b07d7528c
+Subproject commit 7c78a39c531aa2492ed7e92f2ce9dfb2c8c0d3fa