diff --git a/manifests/policy.pp b/manifests/policy.pp
index 47590340..ab548ae5 100644
--- a/manifests/policy.pp
+++ b/manifests/policy.pp
@@ -39,15 +39,15 @@
 #
 class horizon::policy(
   # common parameters
-  $file_mode              = '0640',
-  $file_format            = 'yaml',
-  $purge_config           = false,
+  $file_mode                = '0640',
+  Enum['yaml'] $file_format = 'yaml',
+  Boolean $purge_config     = false,
   # service specific parameters
-  Hash $cinder_policies   = {},
-  Hash $glance_policies   = {},
-  Hash $keystone_policies = {},
-  Hash $neutron_policies  = {},
-  Hash $nova_policies     = {},
+  Hash $cinder_policies     = {},
+  Hash $glance_policies     = {},
+  Hash $keystone_policies   = {},
+  Hash $neutron_policies    = {},
+  Hash $nova_policies       = {},
 ) {
   include horizon::deps
 
diff --git a/manifests/policy/base.pp b/manifests/policy/base.pp
index 7af05720..c3c96443 100644
--- a/manifests/policy/base.pp
+++ b/manifests/policy/base.pp
@@ -16,7 +16,7 @@
 #   Defaults to '0640'
 #
 # [*file_format*]
-#   (Optional) Format for file contents. Valid values
+#   (Optional) Format for file contents. Valid value is 'yaml'
 #   Defaults to 'yaml'.
 #
 # [*purge_config*]
@@ -25,11 +25,11 @@
 #   Defaults to false.
 #
 define horizon::policy::base(
-  String[1] $policy_file = $name,
-  Hash $policies         = {},
-  $file_mode             = '0640',
-  $file_format           = 'yaml',
-  $purge_config          = false,
+  String[1] $policy_file    = $name,
+  Hash $policies            = {},
+  $file_mode                = '0640',
+  Enum['yaml'] $file_format = 'yaml',
+  Boolean $purge_config     = false,
 ) {
   include horizon::deps
   include horizon::params