diff --git a/templates/main.cf.erb b/templates/main.cf.erb
index 9500dcf..d8cc019 100644
--- a/templates/main.cf.erb
+++ b/templates/main.cf.erb
@@ -1,42 +1,42 @@
 # Postfix main configuration file
 #
 # Managed by puppet - module swh-puppet
 #
 # Changes will be overwritten!
 
 smtpd_banner = $myhostname ESMTP $mail_name (Debian/GNU)
 biff = no
 
 # appending .domain is the MUA's job.
 append_dot_mydomain = no
 
 # Uncomment the next line to generate "delayed mail" warnings
 #delay_warning_time = 4h
 
 readme_directory = no
 
 # TLS parameters
 smtpd_tls_cert_file=/etc/ssl/certs/ssl-cert-snakeoil.pem
 smtpd_tls_key_file=/etc/ssl/private/ssl-cert-snakeoil.key
 smtpd_use_tls=yes
 smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
 smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache
 
 # See /usr/share/doc/postfix/TLS_README.gz in the postfix-doc package for
 # information on enabling SSL in the smtp client.
 
 smtpd_relay_restrictions = permit_mynetworks permit_sasl_authenticated defer_unauth_destination
 myhostname = <%= @mailname %>
 alias_maps = hash:/etc/aliases
 alias_database = hash:/etc/aliases
 myorigin = <%= @mailname %>
 mydestination = <%= @destinations.join(", ") %>
 relayhost = <%= @relayhost %>
 mynetworks = <%= @mynetworks.join(" ") %>
 mailbox_size_limit = 0
 recipient_delimiter = +
 inet_interfaces = all
 relay_domains = <%= @relay_destinations.keys.join(", ") %>
 transport_maps = hash:/etc/postfix/transport
-virtual_alias_domains = <%= @virtual_aliases.keys.each { |a| a.split('@').at(-1) }.uniq.join(", ") %>
+virtual_alias_domains = <%= @virtual_aliases.keys.map { |a| a.split('@').at(-1) }.uniq.join(", ") %>
 virtual_alias_maps = hash:/etc/postfix/virtual