diff --git a/resources/templates/provision/grandstream/gxw42xx/{$mac}.xml b/resources/templates/provision/grandstream/gxw42xx/{$mac}.xml
index f631468c81..f9db98e28e 100644
--- a/resources/templates/provision/grandstream/gxw42xx/{$mac}.xml
+++ b/resources/templates/provision/grandstream/gxw42xx/{$mac}.xml
@@ -600,7 +600,7 @@
 <!-- Register Expiration (in minutes. default 1 hour, max 45 days) -->
 <!-- Number: 1 to 64800 -->
 <!-- Mandatory -->
-<P32>3</P32>
+<P32>{math equation="x / y" x=$account.1.register_expires y=40}</P32>
 
 <!-- SIP Registration Failure Retry Wait Time (in seconds. Between 1-3600, default is 30) -->
 <!-- Number: 1 to 3600 -->
@@ -1277,7 +1277,7 @@
 <!-- Register Expiration (in minutes. default 1 hour, max 45 days) -->
 <!-- Number: 1 to 64800 -->
 <!-- Mandatory -->
-<P732>3</P732>
+<P732>{math equation="x / y" x=$account.2.register_expires y=40}</P732>
 
 <!-- SIP Registration Failure Retry Wait Time (in seconds. Between 1-3600, default is 30) -->
 <!-- Number: 1 to 3600 -->
@@ -1950,7 +1950,7 @@
 <!-- Register Expiration (in minutes. default 1 hour, max 45 days) -->
 <!-- Number: 1 to 64800 -->
 <!-- Mandatory -->
-<P532>3</P532>
+<P532>{math equation="x / y" x=$account.3.register_expires y=40}</P532>
 
 <!-- SIP Registration Failure Retry Wait Time (in seconds. Between 1-3600, default is 30) -->
 <!-- Number: 1 to 3600 -->
@@ -2622,7 +2622,7 @@
 <!-- Register Expiration (in minutes. default 1 hour, max 45 days) -->
 <!-- Number: 1 to 64800 -->
 <!-- Mandatory -->
-<P612>3</P612>
+<P612>{math equation="x / y" x=$account.4.register_expires y=40}</P612>
 
 <!-- SIP Registration Failure Retry Wait Time (in seconds. Between 1-3600, default is 30) -->
 <!-- Number: 1 to 3600 -->