diff --git a/puppet/services/neutron-base.yaml b/puppet/services/neutron-base.yaml
index f6339c83a3..bc8dd8d148 100644
--- a/puppet/services/neutron-base.yaml
+++ b/puppet/services/neutron-base.yaml
@@ -42,6 +42,12 @@ parameters:
     type: string
     default: ''
     description: Set to True to enable debugging on all services.
+  EnableConfigPurge:
+    type: boolean
+    default: true
+    description: >
+        Remove configuration that is not generated by TripleO. Setting
+        to false may result in configuration remnants after updates/upgrades.
 
 outputs:
   role_data:
@@ -61,6 +67,7 @@ outputs:
             params:
               PLUGINS: {get_param: NeutronServicePlugins}
         neutron::debug: {get_param: Debug}
+        neutron::purge_config: {get_param: EnableConfigPurge}
         neutron::allow_overlapping_ips: true
         neutron::rabbit_heartbeat_timeout_threshold: 60
         neutron::host: '"%{::fqdn}"'    #NOTE: extra quoting is needed
diff --git a/puppet/services/nova-base.yaml b/puppet/services/nova-base.yaml
index 9dd0c95024..ef7eaaf321 100644
--- a/puppet/services/nova-base.yaml
+++ b/puppet/services/nova-base.yaml
@@ -39,6 +39,12 @@ parameters:
     type: string
     default: ''
     description: Set to True to enable debugging on all services.
+  EnableConfigPurge:
+    type: boolean
+    default: true
+    description: >
+        Remove configuration that is not generated by TripleO. Setting
+        to false may result in configuration remnants after updates/upgrades.
 
 outputs:
   role_data:
@@ -83,6 +89,7 @@ outputs:
           - '%'
           - "%{hiera('mysql_bind_host')}"
         nova::debug: {get_param: Debug}
+        nova::purge_config: {get_param: EnableConfigPurge}
         nova::network::neutron::neutron_project_name: 'service'
         nova::network::neutron::neutron_username: 'neutron'
         nova::network::neutron::dhcp_domain: ''