diff --git a/README.md b/README.md
index d8c24e5..7ebf18f 100644
--- a/README.md
+++ b/README.md
@@ -273,7 +273,7 @@ and the list of domains are included.
 
 REQUIRED
 
-#### Parameters only for deplay: 
+#### Parameters only for deploy: 
 
 ##### `cert_destination_path`
 
@@ -291,7 +291,7 @@ Valid values: `true` `false`
 
 The command used restart any service after cert is deployed
 
-Default value: `''`
+Default value: `'echo restart!'`
 
  
 ## Limitations
diff --git a/manifests/common.pp b/manifests/common.pp
index 0e860e8..3bd3ec0 100644
--- a/manifests/common.pp
+++ b/manifests/common.pp
@@ -5,8 +5,8 @@ class acme_vault::common (
     $user               = $::acme_vault::params::user,
     $group              = $::acme_vault::params::group,
     $home_dir           = $::acme_vault::params::home_dir,
-    $domains            = $::acme_vault::params::domains,
     $contact_email      = $::acme_vault::params::contact_email,
+    $domains            = $::acme_vault::params::domains,
 
     $vault_token        = $::acme_vault::params::vault_token,
     $vault_addr         = $::acme_vault::params::vault_addr,
diff --git a/manifests/params.pp b/manifests/params.pp
index 936a83a..f53f666 100644
--- a/manifests/params.pp
+++ b/manifests/params.pp
@@ -4,28 +4,29 @@ class acme_vault::params {
     $user       = 'acme'
     $group      = 'apache'
     $home_dir   = '/home/acme_vault'
+    $contact_email = ''
+    $domains     = undef
+
+    # authentication
+    $vault_token = undef
+    $vault_addr  = undef
+    $vault_bin   = "${home_dir}/vault"
+
+    $vault_prefix   = '/secret/letsencrypt/'
 
     # whether to use the letsencrypt staging url, set those urls
     $staging     = false
     $staging_url = 'https://acme-staging-v02.api.letsencrypt.org/directory'
     $prod_url    = 'https://acme-v02.api.letsencrypt.org/directory'
-    $contact_email = ''
 
     $acme_revision = 'HEAD'
     $acme_repo_path = "${home_dir}/acme.sh"
     $acme_script    = "${acme_repo_path}/acme.sh"
-    $vault_prefix   = '/secret/letsencrypt/'
-    $domains     = ''
-
-    # authentication
-    $vault_token = ''
-    $vault_addr  = ''
-    $vault_bin   = "${home_dir}/vault"
 
     # lexicon 
-    $lexicon_provider   = ''
-    $lexicon_username   = ''
-    $lexicon_token      = ''
+    $lexicon_provider   = undef 
+    $lexicon_username   = undef 
+    $lexicon_token      = undef 
 
     # settings for deploy
 
diff --git a/metadata.json b/metadata.json
index d94f4fe..3f1896b 100644
--- a/metadata.json
+++ b/metadata.json
@@ -9,33 +9,18 @@
     {
       "name": "puppetlabs-stdlib",
       "version_requirement": ">= 4.13.1 < 5.0.0"
+    },
+    {
+      "name": "puppetlabs-concat",
+      "version_requirement": ">= 1.2.4"
     }
   ],
   "operatingsystem_support": [
-    {
-      "operatingsystem": "Debian",
-      "operatingsystemrelease": [
-        "8"
-      ]
-    },
     {
       "operatingsystem": "RedHat",
       "operatingsystemrelease": [
         "7.0"
       ]
-    },
-    {
-      "operatingsystem": "Ubuntu",
-      "operatingsystemrelease": [
-        "16.04"
-      ]
-    },
-    {
-      "operatingsystem": "windows",
-      "operatingsystemrelease": [
-        "2012 R2"
-      ]
-    }
   ],
   "requirements": [
     {