setkey method's argument is no longer optional (it used to be a no-op
when missing).
diff --git a/Doc/librotor.tex b/Doc/librotor.tex
index af2a283..c333686 100644
--- a/Doc/librotor.tex
+++ b/Doc/librotor.tex
@@ -35,9 +35,8 @@
Rotor objects have the following methods:
\renewcommand{\indexsubitem}{(rotor method)}
-\begin{funcdesc}{setkey}{\optional{key}}
-Sets the rotor's key to \var{key}. If \var{key} is not given, this
-function does nothing\footnote{This is for backwards compatibility.}.
+\begin{funcdesc}{setkey}{key}
+Sets the rotor's key to \var{key}.
\end{funcdesc}
\begin{funcdesc}{encrypt}{plaintext}