diff --git a/data/common.yaml b/data/common.yaml
index 3638cec..ebba0b6 100644
--- a/data/common.yaml
+++ b/data/common.yaml
@@ -3,7 +3,6 @@ lookup_options:
   limits::entries:
     merge: deep
 
-limits::entries: {}
 limits::limits_dir: /etc/security/limits.d
 limits::manage_limits_d_dir: true
 limits::purge_limits_d_dir: true
@@ -18,3 +17,5 @@ limits::limits_file_mode: '0644'
 # until a specific tempalte for each OS and/or major OS version
 # is supplied.
 limits::limits_template: 'generic'
+
+limits::entries: null
diff --git a/manifests/init.pp b/manifests/init.pp
index 3da7cb8..6ca3557 100644
--- a/manifests/init.pp
+++ b/manifests/init.pp
@@ -6,33 +6,51 @@
 # @example
 #   include limits
 #
+# @param limits_dir
+# Directory for individual limits config files
+#
+# @param manage_limits_d_dir
+# Manage $limits_dir itself
+#
+# @param purge_limits_d_dir
+# Purge $limits_dir
+#
+# @param limits_file
+# Basic limits configuration file
+#
+# @param manage_limits_file
+# Manage $limits_file
+#
 # @param limits_file_owner
-# The owner of the limits.conf file.
+# Owner of $limits_file
 #
 # @param limits_file_group
-# The group of the limits.conf file.
+# Group $limits_file
 #
 # @param limits_file_mode
-# The mode of the limits.conf file.
+# Mode $limits_file
 #
 # @param limits_template
-# The name of the template to use for ${limits_file
+# Name of the template to use for $limits_file
+#
+# @param entries
+# limits configuration file(s) entries
 #
 class limits (
-  Hash    $entries,
-  String  $limits_dir,
+  String[1] $limits_dir,
   Boolean $manage_limits_d_dir,
   Boolean $purge_limits_d_dir,
-  String  $limits_file                = $limits::limits_file,
-  Boolean $manage_limits_file         = false,
-  String[1] $limits_file_owner        = $limits::limits_file_owner,
-  String[1] $limits_file_group        = $limits::limits_file_group,
-  String[1] $limits_file_mode         = $limits::limits_file_mode,
-  Optional[String] $limits_template   = $limits::limits_template,
+  String[1] $limits_file,
+  Boolean $manage_limits_file,
+  String[1] $limits_file_owner,
+  String[1] $limits_file_group,
+  String[1] $limits_file_mode,
+  String[1] $limits_template,
+  Optional[Hash[String[1], Hash[Pattern[/\A[a-z][a-z0-9_]*\Z/], Data], 1]] $entries,
 ) {
   if $manage_limits_d_dir {
     file { $limits_dir:
-      ensure  => 'directory',
+      ensure  => directory,
       owner   => 'root',
       group   => 'root',
       force   => true,
@@ -43,7 +61,7 @@
 
   if $manage_limits_file {
     file { $limits_file:
-      ensure  => 'file',
+      ensure  => file,
       owner   => $limits_file_owner,
       group   => $limits_file_group,
       mode    => $limits_file_mode,
@@ -51,9 +69,11 @@
     }
   }
 
-  $entries.each | String $e_name, Hash $e_params | {
-    limits::limits { $e_name:
-      * => $e_params,
+  if $entries !~ Undef {
+    each($entries) | $e_name, $e_params | {
+      limits::limits { $e_name:
+        * => $e_params,
+      }
     }
   }
 }
diff --git a/manifests/limits.pp b/manifests/limits.pp
index e57462c..880f2cc 100644
--- a/manifests/limits.pp
+++ b/manifests/limits.pp
@@ -23,13 +23,13 @@
 # Manages:
 #   limit file in limits.d with the values provided
 define limits::limits (
-  Enum['absent', 'present']     $ensure     = present,
-  Optional[String]              $user       = undef,
-  Optional[String]              $limit_type = undef,
-  Variant[Integer,String,Undef] $hard       = undef,
-  Variant[Integer,String,Undef] $soft       = undef,
-  Variant[Integer,String,Undef] $both       = undef,
-  Optional[String]              $target     = undef,
+  Enum['absent', 'present']          $ensure     = present,
+  Optional[String[1]]                $user       = undef,
+  Optional[String[1]]                $limit_type = undef,
+  Optional[Variant[Integer, String]] $hard       = undef,
+  Optional[Variant[Integer, String]] $soft       = undef,
+  Optional[Variant[Integer, String]] $both       = undef,
+  Optional[String[1]]                $target     = undef,
 ) {
   include limits
 
@@ -65,22 +65,20 @@
     }
   }
 
-  if (!defined(Concat[$target_file])) {
-    concat { $target_file:
-      ensure => $ensure,
-      owner  => 'root',
-      group  => 'root',
-    }
-
-    concat::fragment { "top_${target_file}":
+  ensure_resource('concat::fragment', "top_${target_file}", {
       target  => $target_file,
       content => "# Managed by Puppet\n\n#<domain>    <type> <item>          <value>\n",
       order   => '01',
-    }
-  }
+  })
 
   concat::fragment { "${real_user}_${real_type}":
     target  => $target_file,
     content => template('limits/limits.erb'),
   }
+
+  ensure_resource('concat', $target_file, {
+      ensure => $ensure,
+      owner  => 'root',
+      group  => 'root',
+  })
 }