Using policy overlay

Hello !

I´m with troubles, in trying to load policy overlay,it is /usr/lib/ldap/ppolicy.so. Then I put overlay ppolicy in slapd.conf. So, restart  openldap. But is com error:

Jan 16 16:08:12 defensoria slapd[14010]: @(#) $OpenLDAP: slapd 2.4.23 (Jun 16 2011 02:53:39) $#012#011buildd@murphy:/build/buildd-openldap_2.4.23-7.2-i386-Y1mwvF/openldap-2.4.23/debian/build/servers/slapd Jan 16 16:08:12 defensoria slapd[14010]: overlay "ppolicy" not found Jan 16 16:08:12 defensoria slapd[14010]: slapd stopped. Jan 16 16:08:12 defensoria slapd[14010]: connections_destroy: nothing to destroy.

Anybody Can  to help me ?

Thanks !

Rodrigo Faria