diff --git a/gm.tex b/gm.tex
index fcfd090bd2804d6edbfe2132a41373cf53ade7b1..e2f34ea1cf4a359555a4391589cafa257b77029b 100644
--- a/gm.tex
+++ b/gm.tex
@@ -822,6 +822,7 @@ Each point on the Margin allows an additional person to sleep inside the shelter
 
 \paragraph{Navigation} -- Intelligence + Survival.
 \index{Navigation}
+\index{Marching}
 \label{marching}
 \begin{itemize}