Fix missing parenthesis.
diff --git a/Doc/lib/libdatetime.tex b/Doc/lib/libdatetime.tex
index 4d64499..a0c2788 100644
--- a/Doc/lib/libdatetime.tex
+++ b/Doc/lib/libdatetime.tex
@@ -902,7 +902,7 @@
 
 \begin{methoddesc}{isoweekday}{}
   Return the day of the week as an integer, where Monday is 1 and
-  Sunday is 7.  The same as \code{self.date().isoweekday)}.
+  Sunday is 7.  The same as \code{self.date().isoweekday()}.
   See also \method{weekday()}, \method{isocalendar()}.
 \end{methoddesc}