Duplicate ssh_authorized_key[barman]

[deric]

I've configured a backup server and now on a DB server I'm hitting following error:

A duplicate resource was found while collecting exported resources, with the type and title Ssh_authorized_key[barman]

backup server:

  class { 'postgresql::globals':
    manage_package_repo => true,
  }->
  class { 'barman': }

  @@host { $::fqdn:
    ensure       => 'present',
    name         => $::fqdn,
    host_aliases => $::hostname,
    ip           => pick($::ipaddress_eth0, $::ipaddress),
  }
  Host <<| |>>

DB server:

include barman::postgres

Am I missing something?