diff --git a/manifests/federation/openidc.pp b/manifests/federation/openidc.pp
index 27e541c2e..53529570e 100644
--- a/manifests/federation/openidc.pp
+++ b/manifests/federation/openidc.pp
@@ -163,7 +163,11 @@ class keystone::federation::openidc (
     }
   }
 
-  $memcached_servers_real = join(any2array($memcached_servers), ' ')
+  if $memcached_servers != undef {
+    $memcached_servers_real = join(any2array($memcached_servers), ' ')
+  } else {
+    $memcached_servers_real = undef
+  }
 
   # Note: if puppet-apache modify these values, this needs to be updated
   if $template_order <= 330 or $template_order >= 999 {
diff --git a/templates/openidc.conf.erb b/templates/openidc.conf.erb
index 63a348449..687baf4b3 100644
--- a/templates/openidc.conf.erb
+++ b/templates/openidc.conf.erb
@@ -22,7 +22,7 @@
 <%- if scope['::keystone::federation::openidc::openidc_cache_clean_interval'] != nil -%>
   OIDCCacheFileCleanInterval scope['::keystone::federation::openidc::openidc_cache_clean_interval'] %>
 <%- end -%>
-<%- if scope['::keystone::federation::openidc::memcached_servers_real'] -%>
+<%- if scope['::keystone::federation::openidc::memcached_servers_real'] != nil -%>
   OIDCMemCacheServers "<%= scope['::keystone::federation::openidc::memcached_servers_real'] %>"
 <%- end -%>
 <%- if scope['::keystone::federation::openidc::redis_server'] != nil -%>