diff --git a/wp-nginx-map.php b/wp-nginx-map.php
index f8edaa29a6dcd16ba8ca4c911717156748a6bf49..b086c225147542c509545a66ef39ffe025ac313f 100644
--- a/wp-nginx-map.php
+++ b/wp-nginx-map.php
@@ -3,7 +3,8 @@
 // wp-nginx-map.php
 //
 // Stampa una mappa delle assegnazioni blog -> backend, per NGINX.
-
+// IP interno del master.
+define('NOBLOGS_MASTER', '172.16.1.10');
 
 // Load wordpress api.
 define('WP_CACHE',false);
@@ -24,7 +25,7 @@ function printline($s) {
 function backend_to_http_endpoint($backend) {
   if (substr($backend, 0, 8) != 'backend_') {
     error_log('diamine, di questo backend non so che farmene: ' . $backend);
-    return 'localhost:82';
+    return NOBLOGS_MASTER . ':82';
   }
   $id = substr($backend, 8);
   return '172.16.1.' . $id . ':82';
@@ -38,7 +39,7 @@ function generate_map() {
   $blogs = get_blogs();
 
   printline('map $http_host $backend_noblogs {');
-  printline(' default http://localhost:82;');
+  printline(' default http://' . NOBLOGS_MASTER . ':82;');
   foreach ($blogs as $blog) {
     $blog_id = $blog->blog_id;
     $backend_id = $wpdb_hash->lookup($blog_id);