diff --git a/manifests/apache/conf.pp b/manifests/apache/conf.pp
index c5325d0..da69fc6 100644
--- a/manifests/apache/conf.pp
+++ b/manifests/apache/conf.pp
@@ -36,10 +36,10 @@
   Optional[String[1]] $ldap_bind_authoritative = undef,
   Boolean $ldap_require_group                  = $puppetboard::ldap_require_group,
   Optional[String[1]] $ldap_require_group_dn   = undef,
-  Optional[String] $ldap_require_user          = undef,
-  Optional[String] $ldap_require_dn            = undef,
-  Optional[String] $ldap_require_attribute     = undef,
-  Optional[String] $ldap_require_filter        = undef,
+  Optional[String[1]] $ldap_require_user          = undef,
+  Optional[String[1]] $ldap_require_dn            = undef,
+  Optional[String[1]] $ldap_require_attribute     = undef,
+  Optional[String[1]] $ldap_require_filter        = undef,
   Stdlib::Absolutepath $virtualenv_dir         = $puppetboard::virtualenv_dir,
 ) {
   $wsgi = $facts['os']['family'] ? {
diff --git a/manifests/apache/vhost.pp b/manifests/apache/vhost.pp
index 3c5f19e..2264141 100644
--- a/manifests/apache/vhost.pp
+++ b/manifests/apache/vhost.pp
@@ -47,10 +47,10 @@
   Optional[String[1]] $ldap_bind_authoritative = undef,
   Boolean $ldap_require_group                  = $puppetboard::ldap_require_group,
   Optional[String[1]] $ldap_require_group_dn   = undef,
-  Optional[String] $ldap_require_user          = undef,
-  Optional[String] $ldap_require_dn            = undef,
-  Optional[String] $ldap_require_attribute     = undef,
-  Optional[String] $ldap_require_filter        = undef,
+  Optional[String[1]] $ldap_require_user          = undef,
+  Optional[String[1]] $ldap_require_dn            = undef,
+  Optional[String[1]] $ldap_require_attribute     = undef,
+  Optional[String[1]] $ldap_require_filter        = undef,
   Stdlib::Absolutepath $virtualenv_dir         = $puppetboard::virtualenv_dir,
   Hash $custom_apache_parameters               = {},
 ) {