diff --git a/manifests/allow.pp b/manifests/allow.pp
index d597f5d..fb026a1 100644
--- a/manifests/allow.pp
+++ b/manifests/allow.pp
@@ -1,76 +1,76 @@
 # Class: sudo::allow
 #
 # This class allows you to take complete advantage of automatic parameter
 # lookup using a Hiera database. Providing a singleton class that accepts
 # arrays in the parameters makes it possible to implement specific user
 # or group configuration in Hiera, whereas the use of defined types is
 # normally restricted to Puppet manifests.
 #
 # Furthermore, having separate parameters for "add" and "replace" modes
 # allows you to take full advantage of inheritance in the Hiera database
 # while still allowing for exceptions if required.
 #
 # This class works best with Puppet 3.0 or higher.
 #
 # Parameters:
 #   [*add_users*]
 #     Define the set of users with sudo privileges by getting all values in
 #     the hierarchy for this key, then flattening them into a single array
 #     of unique values.
 #     Default: empty array
 #
 #   [*add_groups*]
 #     Define the set of groups with sudo privileges by getting all values in
 #     the hierarchy for this key, then flattening them into a single array
 #     of unique values.
 #     Default: empty array
 #
 #   [*replace_users*]
 #     Override any values specified in add_users. If you specify this value
 #     in your manifest or Hiera database, the contents of "add_users" will
 #     be ignored. With Hiera, a standard priority lookup is used. Note that
 #     if replace_users is specified at ANY level of the hierarchy, then
 #     add_users is ignored at EVERY level of the hierarchy.
 #     Default: undef
 #
 #   [*replace_groups*]
 #     Override any values specified in add_groups. If you specify this value
 #     in your manifest or Hiera database, the contents of "add_groups" will
 #     be ignored. With Hiera, a standard priority lookup is used. Note that
 #     if replace_groups is specified at ANY level of the hierarchy, then
 #     add_groups is ignored at EVERY level of the hierarchy.
 #     Default: undef
 #
 # Actions:
 #   Creates file in sudoers.d that permits specific users and groups to sudo.
 #
 # Sample Usage:
 #   class { 'sudo::allow':
 #     add_users  => ['jsmith'],
 #     add_groups => ['wheel'],
 #   }
 #
 # [Remember: No empty lines between comments and class definition]
 class sudo::allow(
   $add_users = [],
   $add_groups = [],
   $replace_users = undef,
   $replace_groups = undef
 ) {
   # TODO validate that all input is arrays
 
   if $replace_users != undef {
     $users = $replace_users
   } else {
-    $users = hiera_array("${module_name}::allow::add_users", $add_users)
+    $users = lookup("${module_name}::allow::add_users", Array, 'unique', $add_users)
   }
   if $replace_groups != undef {
     $groups = $replace_groups
   } else {
-    $groups = hiera_array("${module_name}::allow::add_groups", $add_groups)
+    $groups = lookup("${module_name}::allow::add_groups", Array, 'unique', $add_groups)
   }
 
   sudo::conf { 'sudo_users_groups':
     content  => template("${module_name}/users_groups.erb"),
   }
 }