diff --git a/ansible/inventories/sifi.yaml b/ansible/inventories/sifi.yaml
index 0214113..161b5dc 100644
--- a/ansible/inventories/sifi.yaml
+++ b/ansible/inventories/sifi.yaml
@@ -1,12 +1,13 @@
 #SIFI
 sifi:
   children:
-    nameserver:
+    opn:
       hosts:
         ns1.sifi.isti.cnr.it:
           ansible_host:  146.48.108.51
+    nameserver:
+      hosts:
+        opn:
     workers:
       hosts:
-        worker1.sifi.isti.cnr.it:    
-
-          
\ No newline at end of file
+        worker1.sifi.isti.cnr.it:    
\ No newline at end of file