diff --git a/Doc/lib/emailiter.tex b/Doc/lib/emailiter.tex
index 9180ac2..d1a8f98 100644
--- a/Doc/lib/emailiter.tex
+++ b/Doc/lib/emailiter.tex
@@ -6,13 +6,15 @@
 provides some useful higher level iterations over message object
 trees.
 
-\begin{funcdesc}{body_line_iterator}{msg}
+\begin{funcdesc}{body_line_iterator}{msg\optional{, decode}}
 This iterates over all the payloads in all the subparts of \var{msg},
 returning the string payloads line-by-line.  It skips over all the
 subpart headers, and it skips over any subpart with a payload that
 isn't a Python string.  This is somewhat equivalent to reading the
 flat text representation of the message from a file using
 \method{readline()}, skipping over all the intervening headers.
+
+Optional \var{decode} is passed through to \method{Message.get_payload()}.
 \end{funcdesc}
 
 \begin{funcdesc}{typed_subpart_iterator}{msg\optional{,