diff --git a/Doc/lib/libstdtypes.tex b/Doc/lib/libstdtypes.tex
index 597aab1..01ca630 100644
--- a/Doc/lib/libstdtypes.tex
+++ b/Doc/lib/libstdtypes.tex
@@ -710,15 +710,16 @@
 
 It is written as \code{Ellipsis}.
 
-\subsubsection{File Objects \label{bltin-file-objects}}
+\subsubsection{File Objects\obindex{file}
+               \label{bltin-file-objects}}
 
-File objects are implemented using \C{}'s \code{stdio} package and can be
-created with the built-in function \function{open()} described Section
+File objects are implemented using \C{}'s \code{stdio}
+package and can be created with the built-in function
+\function{open()}\bifuncindex{open} described Section
 \ref{built-in-funcs}, ``Built-in Functions.''  They are also returned
 by some other built-in functions and methods, e.g.,
 \function{posix.popen()} and \function{posix.fdopen()} and the
 \method{makefile()} method of socket objects.
-\bifuncindex{open}
 \refbimodindex{posix}
 \refbimodindex{socket}