diff --git a/manifests/params.pp b/manifests/params.pp
index 4b0f55a..7470a1d 100644
--- a/manifests/params.pp
+++ b/manifests/params.pp
@@ -1,282 +1,282 @@
 class sudo::params {
   $content_base     = "${module_name}/"
   $config_file_mode = '0440'
   $config_dir_mode  = '0550'
 
   case $facts['os']['family'] {
     'Debian': {
       case $facts['os']['name'] {
         'Ubuntu': {
           $content     = "${content_base}sudoers.ubuntu.erb"
           $secure_path = '/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/opt/puppetlabs/bin:/snap/bin'
         }
         default: {
           if (versioncmp($facts['os']['release']['major'], '7') >= 0) or
           ($facts['os']['release']['major'] =~ /\/sid/) or
           ($facts['os']['release']['major'] =~ /Kali/) {
             $content = "${content_base}sudoers.debian.erb"
             $secure_path = '/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/opt/puppetlabs/bin'
           } else {
             $content     = "${content_base}sudoers.olddebian.erb"
             $secure_path = undef
           }
         }
       }
       $package            = 'sudo'
       $package_ldap       = 'sudo-ldap'
       $package_ensure     = 'present'
       $package_source     = ''
       $package_admin_file = ''
       $config_file        = '/etc/sudoers'
       $config_dir         = '/etc/sudoers.d'
       $config_file_group  = 'root'
       $config_dir_keepme  = false
-      $package_provider   = ''
+      $package_provider   = undef
     }
     'RedHat': {
       $package = 'sudo'
       # in redhat sudo package is already compiled for ldap support
       $package_ldap = $package
 
       # rhel 5.0 to 5.4 use sudo 1.6.9 which does not support
       # includedir, so we have to make sure sudo 1.7 (comes with rhel
       # 5.5) is installed.
       $package_ensure     = $facts['os']['release']['full'] ? {
         /^5.[01234]$/ => 'latest',
         default       => 'present',
       }
       $package_source     = ''
       $package_admin_file = ''
       $config_file        = '/etc/sudoers'
       $config_dir         = '/etc/sudoers.d'
       case $facts['os']['release']['full'] {
         /^5/: {
           $content     = "${content_base}sudoers.rhel5.erb"
           $secure_path = undef
         }
         /^6/: {
           $content     = "${content_base}sudoers.rhel6.erb"
           $secure_path = '/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin'
         }
         /^7/: {
           $content     = "${content_base}sudoers.rhel7.erb"
           $secure_path = '/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/opt/puppetlabs/bin'
         }
         /^8/: {
           $content     = "${content_base}sudoers.rhel8.erb"
           $secure_path = '/sbin:/bin:/usr/sbin:/usr/bin:/opt/puppetlabs/bin'
         }
         default: {
           $content     = "${content_base}sudoers.rhel8.erb"
           $secure_path = '/sbin:/bin:/usr/sbin:/usr/bin:/opt/puppetlabs/bin'
         }
       }
       $config_file_group  = 'root'
       $config_dir_keepme  = false
-      $package_provider   = ''
+      $package_provider   = undef
     }
     'Suse': {
       $package            = 'sudo'
       $package_ldap       = $package
       $package_ensure     = 'present'
       $package_source     = ''
       $package_admin_file = ''
       $config_file        = '/etc/sudoers'
       $config_dir         = '/etc/sudoers.d'
       $content            = "${content_base}sudoers.suse.erb"
       $secure_path        = '/usr/sbin:/usr/bin:/sbin:/bin:/opt/puppetlabs/bin'
       $config_file_group  = 'root'
       $config_dir_keepme  = false
-      $package_provider   = ''
+      $package_provider   = undef
     }
     'Solaris': {
       case $facts['os']['name'] {
         'OmniOS': {
           $package            = 'sudo'
           $package_ldap       = undef
           $package_ensure     = 'present'
           $package_source     = ''
           $package_admin_file = ''
           $config_file        = '/etc/sudoers'
           $config_dir         = '/etc/sudoers.d'
           $content            = "${content_base}sudoers.omnios.erb"
           $secure_path        = undef
           $config_file_group  = 'root'
           $config_dir_keepme  = false
-          $package_provider   = ''
+          $package_provider   = undef
         }
         'SmartOS': {
           $package            = 'sudo'
           $package_ldap       = undef
           $package_ensure     = 'present'
           $package_source     = ''
           $package_admin_file = ''
           $config_file        = '/opt/local/etc/sudoers'
           $config_dir         = '/opt/local/etc/sudoers.d'
           $content            = "${content_base}sudoers.smartos.erb"
           $secure_path        = undef
           $config_file_group  = 'root'
           $config_dir_keepme  = false
-          $package_provider   = ''
+          $package_provider   = undef
         }
         default: {
           case $::kernelrelease {
             '5.11': {
               $package            = 'pkg://solaris/security/sudo'
               $package_ldap       = undef
               $package_ensure     = 'present'
               $package_source     = ''
               $package_admin_file = ''
               $config_file        = '/etc/sudoers'
               $config_dir         = '/etc/sudoers.d'
               $content            = "${content_base}sudoers.solaris.erb"
               $secure_path        = undef
               $config_file_group  = 'root'
               $config_dir_keepme  = false
-              $package_provider   = ''
+              $package_provider   = undef
             }
             '5.10': {
               $package            = 'TCMsudo'
               $package_ldap       = undef
               $package_ensure     = 'present'
               $package_source     = "http://www.sudo.ws/sudo/dist/packages/Solaris/10/TCMsudo-1.8.9p5-${facts['os']['hardware']}.pkg.gz"
               $package_admin_file = '/var/sadm/install/admin/puppet'
               $config_file        = '/etc/sudoers'
               $config_dir         = '/etc/sudoers.d'
               $content            = "${content_base}sudoers.solaris.erb"
               $secure_path        = undef
               $config_file_group  = 'root'
               $config_dir_keepme  = false
-              $package_provider   = ''
+              $package_provider   = undef
             }
             default: {
               fail("Unsupported platform: ${facts['os']['family']}/${facts['os']['name']}/${::kernelrelease}")
             }
           }
         }
       }
     }
     'FreeBSD': {
       $package            = 'security/sudo'
       $package_ldap       = undef
       $package_ensure     = 'present'
       $package_source     = ''
       $package_admin_file = ''
       $config_file        = '/usr/local/etc/sudoers'
       $config_dir         = '/usr/local/etc/sudoers.d'
       $content            = "${content_base}sudoers.freebsd.erb"
       $secure_path        = '/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/opt/puppetlabs/bin'
       $config_file_group  = 'wheel'
       $config_dir_keepme  = true
-      $package_provider   = ''
+      $package_provider   = undef
     }
     'OpenBSD': {
       if (versioncmp($::kernelversion, '5.8') < 0) {
         $package = undef
       } else {
         $package = 'sudo'
       }
       $package_ldap       = undef
       $package_ensure     = 'present'
       $package_source     = ''
       $package_admin_file = ''
       $config_file        = '/etc/sudoers'
       $config_dir         = '/etc/sudoers.d'
       $content            = "${content_base}sudoers.openbsd.erb"
       $config_file_group  = 'wheel'
       $config_dir_keepme  = false
-      $package_provider   = ''
+      $package_provider   = undef
     }
     'AIX': {
       $package            = 'sudo'
       $package_ldap       = undef
       $package_ensure     = 'present'
       $package_source     = 'http://www.sudo.ws/sudo/dist/packages/AIX/5.3/sudo-1.8.27-1.aix53.rpm'
       $package_admin_file = ''
       $config_file        = '/etc/sudoers'
       $config_dir         = '/etc/sudoers.d'
       $content            = "${content_base}sudoers.aix.erb"
       $secure_path        = undef
       $config_file_group  = 'system'
       $config_dir_keepme  = false
       $package_provider   = 'rpm'
     }
     'Darwin': {
       $package            = undef
       $package_ldap       = undef
       $package_ensure     = 'present'
       $package_source     = ''
       $package_admin_file = ''
       $config_file        = '/etc/sudoers'
       $config_dir         = '/etc/sudoers.d'
       $content            = "${content_base}sudoers.darwin.erb"
       $secure_path        = undef
       $config_file_group  = 'wheel'
       $config_dir_keepme  = false
-      $package_provider   = ''
+      $package_provider   = undef
     }
     default: {
       case $facts['os']['name'] {
         'Gentoo': {
           $package            = 'sudo'
           $package_ldap       = $package
           $package_ensure     = 'present'
           $package_source     = ''
           $package_admin_file = ''
           $config_file        = '/etc/sudoers'
           $config_dir         = '/etc/sudoers.d'
           $content            = "${content_base}sudoers.gentoo.erb"
           $secure_path        = undef
           $config_file_group  = 'root'
           $config_dir_keepme  = false
-          $package_provider   = ''
+          $package_provider   = undef
         }
         /^(Arch|Manjaro)(.{0}|linux)$/: {
           $package            = 'sudo'
           $package_ldap       = $package
           $package_ensure     = 'present'
           $package_source     = ''
           $package_admin_file = ''
           $config_file        = '/etc/sudoers'
           $config_dir         = '/etc/sudoers.d'
           $content            = "${content_base}sudoers.archlinux.erb"
           $secure_path        = undef
           $config_file_group  = 'root'
           $config_dir_keepme  = false
-          $package_provider   = ''
+          $package_provider   = undef
         }
         'Amazon': {
           $package            = 'sudo'
           $package_ldap       = $package
           $package_ensure     = 'present'
           $package_source     = ''
           $package_admin_file = ''
           $config_file        = '/etc/sudoers'
           $config_dir         = '/etc/sudoers.d'
           case $facts['os']['release']['full'] {
             /^5/: {
               $content     = "${content_base}sudoers.rhel5.erb"
               $secure_path = undef
             }
             /^6/: {
               $content     = "${content_base}sudoers.rhel6.erb"
               $secure_path = '/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin'
             }
             default: {
               $content     = "${content_base}sudoers.rhel6.erb"
               $secure_path = '/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin'
             }
           }
           $config_file_group  = 'root'
           $config_dir_keepme  = false
-          $package_provider   = ''
+          $package_provider   = undef
         }
         default: {
           fail("Unsupported platform: ${facts['os']['family']}/${facts['os']['name']}")
         }
       }
       $package_source = ''
       $package_admin_file = ''
     }
   }
 }