diff --git a/doc/pyOpenSSL.tex b/doc/pyOpenSSL.tex
index 575eb8e..fa7638d 100644
--- a/doc/pyOpenSSL.tex
+++ b/doc/pyOpenSSL.tex
@@ -322,7 +322,8 @@
 \end{methoddesc}
 
 \begin{methoddesc}[X509]{get_signature_algorithm}{}
-Return the signature algorithem used in the certificate.
+Return the signature algorithm used in the certificate.  If the algorithm is
+undefined, raise \code{ValueError}.
 \end{methoddesc}
 
 \begin{methoddesc}[X509]{get_subject}{}