diff --git a/api-ref/src/wadls/networking-api/src/wadl/firewalls.wadl b/api-ref/src/wadls/networking-api/src/wadl/firewalls.wadl
index f2664aad5..9d8d54ebf 100644
--- a/api-ref/src/wadls/networking-api/src/wadl/firewalls.wadl
+++ b/api-ref/src/wadls/networking-api/src/wadl/firewalls.wadl
@@ -117,6 +117,10 @@
             <para>
                 The firewall must be associated with a firewall policy.
             </para>
+            <para>
+                If <code>admin_state_up</code> is <code>false</code>,
+                the firewall would block all traffic.
+            </para>
         </wadl:doc>
         <request>
             <representation mediaType="application/json">