diff --git a/Doc/lib/libtraceback.tex b/Doc/lib/libtraceback.tex
index 1ad165c..b7f61ac 100644
--- a/Doc/lib/libtraceback.tex
+++ b/Doc/lib/libtraceback.tex
@@ -48,7 +48,7 @@
 variables.)
 \end{funcdesc}
 
-\begin{funcdesc}{format_exc}{\optional{limit\optional{, file}}}
+\begin{funcdesc}{format_exc}{\optional{limit}}
 This is like \code{print_exc(\var{limit})} but returns a string
 instead of printing to a file.
 \versionadded{2.4}