I have a SLES SP3 server that I am attempting to use ipset on.

I have made a simple testing ipset using the following:

ipset -N sftpext hash:ip
That works and I am able to add IP addresses to the ipset. However, I can't use the set in an iptables rule

iptables -A INPUT -m set --match-set sftpext src -j ACCEPT
I get the following error:
iptables: No chain/target/match by that name
Any help would be appreciated.