diff --git a/packstack/plugins/nova_300.py b/packstack/plugins/nova_300.py
index 1899edb3e..f07a9788a 100644
--- a/packstack/plugins/nova_300.py
+++ b/packstack/plugins/nova_300.py
@@ -167,7 +167,7 @@ def initConfig(controller):
                         "'name':'default'}, {...}] "),
              "OPTION_LIST": [],
              "VALIDATORS": [],
-             "DEFAULT_VALUE": "",
+             "DEFAULT_VALUE": "[]",
              "MASK_INPUT": False,
              "LOOSE_VALIDATION": True,
              "CONF_NAME": "CONFIG_NOVA_PCI_ALIAS",
@@ -182,7 +182,7 @@ def initConfig(controller):
                         "'name':'default'}, {...}]"),
              "OPTION_LIST": [],
              "VALIDATORS": [],
-             "DEFAULT_VALUE": "",
+             "DEFAULT_VALUE": "[]",
              "MASK_INPUT": False,
              "LOOSE_VALIDATION": True,
              "CONF_NAME": "CONFIG_NOVA_PCI_PASSTHROUGH_WHITELIST",
@@ -438,12 +438,6 @@ def create_common_manifest(config, messages):
     dbacces_hosts = set([config.get('CONFIG_CONTROLLER_HOST')])
     dbacces_hosts |= network_hosts
 
-    if config['CONFIG_NOVA_PCI_PASSTHROUGH_WHITELIST'] == '':
-        config['CONFIG_NOVA_PCI_PASSTHROUGH_WHITELIST'] = []
-
-    if config['CONFIG_NOVA_PCI_ALIAS'] == '':
-        config['CONFIG_NOVA_PCI_ALIAS'] = []
-
     for host in filtered_hosts(config):
         pw_in_sqlconn = False
         host = host.strip()
diff --git a/packstack/puppet/modules/packstack/manifests/nova/api.pp b/packstack/puppet/modules/packstack/manifests/nova/api.pp
index 59d3714b3..52100562a 100644
--- a/packstack/puppet/modules/packstack/manifests/nova/api.pp
+++ b/packstack/puppet/modules/packstack/manifests/nova/api.pp
@@ -16,11 +16,7 @@ class packstack::nova::api ()
       auth_url             => lookup('CONFIG_KEYSTONE_ADMIN_URL'),
     }
 
-    if lookup('CONFIG_NOVA_PCI_ALIAS') == '' {
-      $pci_alias = []
-    } else {
-      $pci_alias = lookup('CONFIG_NOVA_PCI_ALIAS')
-    }
+    $pci_alias = parsejson(lookup('CONFIG_NOVA_PCI_ALIAS'))
 
     class { 'nova::pci':
       aliases => $pci_alias,
diff --git a/packstack/puppet/modules/packstack/manifests/nova/compute.pp b/packstack/puppet/modules/packstack/manifests/nova/compute.pp
index e0988bf89..856d32651 100644
--- a/packstack/puppet/modules/packstack/manifests/nova/compute.pp
+++ b/packstack/puppet/modules/packstack/manifests/nova/compute.pp
@@ -69,7 +69,7 @@ class packstack::nova::compute ()
     }
 
     class { 'nova::compute::pci':
-      passthrough => lookup('CONFIG_NOVA_PCI_PASSTHROUGH_WHITELIST')
+      passthrough => parsejson(lookup('CONFIG_NOVA_PCI_PASSTHROUGH_WHITELIST'))
     }
 
     class { 'nova::compute':