diff --git a/manifests/server/postgis.pp b/manifests/server/postgis.pp
index a43e4c1..715207a 100644
--- a/manifests/server/postgis.pp
+++ b/manifests/server/postgis.pp
@@ -1,24 +1,23 @@
 # Install the postgis postgresql packaging. See README.md for more details.
 class postgresql::server::postgis (
-  $package_name   = $postgresql::params::postgis_package_name,
+  String $package_name   = $postgresql::params::postgis_package_name,
   $package_ensure = 'present'
 ) inherits postgresql::params {
-  validate_string($package_name)
 
   package { 'postgresql-postgis':
     ensure => $package_ensure,
     name   => $package_name,
     tag    => 'postgresql',
   }
 
   anchor { 'postgresql::server::postgis::start': }
   -> Class['postgresql::server::install']
   -> Package['postgresql-postgis']
   -> Class['postgresql::server::service']
   -> anchor { 'postgresql::server::postgis::end': }
 
   if $postgresql::globals::manage_package_repo {
     Class['postgresql::repo']
     -> Package['postgresql-postgis']
   }
 }