fix minor markup mistake
diff --git a/doc/pyOpenSSL.tex b/doc/pyOpenSSL.tex
index 7b9bdbb..564e6bb 100644
--- a/doc/pyOpenSSL.tex
+++ b/doc/pyOpenSSL.tex
@@ -299,7 +299,7 @@
\var{certificate} is a \code{X509} instance corresponding to the private key
which generated the signature. \var{signature} is a \var{str} instance giving
the signature itself. \var{data} is a \var{str} instance giving the data to
-which the signature applies. \var{digest| is a \var{str} instance naming the
+which the signature applies. \var{digest} is a \var{str} instance naming the
message digest type of the signature, for example \code{``sha1''}.
\end{funcdesc}