diff --git a/doc/SSH_with_PIV_and_PKCS11.adoc b/doc/SSH_with_PIV_and_PKCS11.adoc
index c75ba55..525c5d9 100644
--- a/doc/SSH_with_PIV_and_PKCS11.adoc
+++ b/doc/SSH_with_PIV_and_PKCS11.adoc
@@ -11,6 +11,8 @@ Prerequisites
 * a YubiKey Neo with the PIV applet loaded
 * the yubico-piv-tool software
 * the OpenSC software
+* OpenSSH
+** on OS X for ssh-agent to work a newer OpenSSH than is delivered with the system
 
 Steps
 -----
@@ -44,3 +46,13 @@ the target system.
 6. Authenticate to the target system using the new key:
 
    $ ssh -I $OPENSC_LIBS/opensc-pkcs11.so user@remote.example.com
+
+7. This can also be setup to work with ssh-agent: (Optional)
+
+   $ ssh-add -s $OPENSC_LIBS/opensc-pkcs11.so
++
+NOTE: On OS X this typically requires installation of a third-party OpenSSH from Homebrew or the like and using that ssh-agent.
++
+To See that the ssh-agent correctly finds that key and getting the public key in correct format:
+
+   $ ssh-add -L