diff --git a/chap-cheri-x86-64.tex b/chap-cheri-x86-64.tex
index 0fb40c6f..ce287234 100644
--- a/chap-cheri-x86-64.tex
+++ b/chap-cheri-x86-64.tex
@@ -1,4 +1,4 @@
-\chapter{The CHERI-x86-64 Instruction-Set Architecture (Sketch)}
+\chapter[The CHERI-x86-64 ISA (Sketch)]{The CHERI-x86-64 Instruction-Set Architecture (Sketch)}
 \label{chap:cheri-x86-64}
 
 \rwnote{New introduction is required, and some change of pitch.}