diff --git a/book/external/TeachBooks b/book/external/TeachBooks
index 1ceeb77..ba87520 160000
--- a/book/external/TeachBooks
+++ b/book/external/TeachBooks
@@ -1 +1 @@
-Subproject commit 1ceeb77e7afffde466c8feb0c6a1479e40907c33
+Subproject commit ba8752053a5a4c70d8dacc77e65433f5bfb5a318