diff --git a/manifests/init.pp b/manifests/init.pp
index 2fb5e7be..d98b78d2 100644
--- a/manifests/init.pp
+++ b/manifests/init.pp
@@ -18,9 +18,9 @@
 #   Defaults to false.
 #
 class gnocchi (
-  $package_ensure   = 'present',
-  $coordination_url = $facts['os_service_default'],
-  $purge_config     = false,
+  $package_ensure       = 'present',
+  $coordination_url     = $facts['os_service_default'],
+  Boolean $purge_config = false,
 ) inherits gnocchi::params {
 
   include gnocchi::deps
diff --git a/manifests/policy.pp b/manifests/policy.pp
index 214376e8..0c7c86f5 100644
--- a/manifests/policy.pp
+++ b/manifests/policy.pp
@@ -52,7 +52,7 @@ class gnocchi::policy (
   $policy_path          = '/etc/gnocchi/policy.yaml',
   $policy_default_rule  = $facts['os_service_default'],
   $policy_dirs          = $facts['os_service_default'],
-  $purge_config         = false,
+  Boolean $purge_config = false,
 ) {
 
   include gnocchi::deps