diff --git a/docs/f2b.conf.sample b/docs/f2b.conf.sample
index e86c6a9..75364ab 100644
--- a/docs/f2b.conf.sample
+++ b/docs/f2b.conf.sample
@@ -23,8 +23,8 @@ load  = libf2b_filter_preg.so
 [backend:exec-ipset]
 load  = libf2b_backend_exec.so
 start = /sbin/ipset -! create  <ID> hash:ip
-start = /sbin/iptables -I INPUT -m set --match-set <ID> -j DROP
-stop  = /sbin/iptables -D INPUT -m set --match-set <ID> -j DROP
+start = /sbin/iptables -I INPUT -m set --match-set <ID> src -j DROP
+stop  = /sbin/iptables -D INPUT -m set --match-set <ID> src -j DROP
 stop  = /sbin/ipset -! destroy <ID>
 ban   = /sbin/ipset -! add     <ID> <IP>
 check = /sbin/ipset -! test    <ID> <IP>