diff --git a/doc/apps/crl.pod b/doc/apps/crl.pod
index a40c873b95689523487cf5c56a5de942eafef808..1ad76a5f8c13ea8c21aa62fb8e5196be5e26e7db 100644
--- a/doc/apps/crl.pod
+++ b/doc/apps/crl.pod
@@ -62,6 +62,11 @@ don't output the encoded version of the CRL.
 output a hash of the issuer name. This can be use to lookup CRLs in
 a directory by issuer name.
 
+=item B<-hash_old>
+
+outputs the "hash" of the CRL issuer name using the older algorithm
+as used by OpenSSL versions before 1.0.0.
+
 =item B<-issuer>
 
 output the issuer name.