diff --git a/Doc/mac/libmacui.tex b/Doc/mac/libmacui.tex
index c58edd0..51ac023 100644
--- a/Doc/mac/libmacui.tex
+++ b/Doc/mac/libmacui.tex
@@ -143,6 +143,7 @@
 \class{unicode}, \class{FSSpec}, \class{FSRef} and subtypes thereof are
 acceptable.
 
+\index{Navigation Services}
 For a description of the other arguments please see the Apple Navigation
 Services documentation and the \module{EasyDialogs} source code.
 \end{funcdesc}