[stunnel-users] xforwardedfor in config

I am new to stunnel and the ssl world. I'm trying to get stunnel to work with haproxy for load balancing https requests. In the haproxy documentation it says that the stunnel.conf should look like this

cert=/etc/stunnel/stunnel.pem setuid=stunnel setgid=proxy

socket=l:TCP_NODELAY=1 socket=r:TCP_NODELAY=1

[https] accept=192.168.1.1:443 connect=192.168.1.1:80 xforwardedfor=yes

However, when I try to start the stunnel service I get this

Starting stunnel: file /etc/stunnel/stunnel.conf line 9: Specified option name is not valid here

If I comment out the xforwardedfor parameter, it starts.

Any help is greatly appreciated.

Thank you,

Jill Rochelle