diff --git a/resources/templates/provision/grandstream/gxw40xx/{$mac}.xml b/resources/templates/provision/grandstream/gxw40xx/{$mac}.xml
index 91fe915d17..9d34d03b53 100644
--- a/resources/templates/provision/grandstream/gxw40xx/{$mac}.xml
+++ b/resources/templates/provision/grandstream/gxw40xx/{$mac}.xml
@@ -343,7 +343,7 @@
     <!-- Register Expiration (in minutes. default 1 hour, max 45 days) -->
     <!-- Number: 1 to 64800 -->
     <!-- Mandatory -->
-    <P32>3</P32>
+    <P32>{math equation="x / y" x=$account.1.register_expires y=40}</P32>
     <!-- Reregister before Expiration -->
     <!-- Number -->
     <!-- Mandatory -->
@@ -876,7 +876,7 @@
     <!-- Register Expiration (in minutes. default 1 hour, max 45 days) -->
     <!-- Number: 1 to 64800 -->
     <!-- Mandatory -->
-    <P732>3</P732>
+    <P732>{math equation="x / y" x=$account.2.register_expires y=40}</P732>
     <!-- Reregister before Expiration -->
     <!-- Number -->
     <!-- Mandatory -->
@@ -1401,7 +1401,7 @@
     <!-- 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>
     <!-- Reregister before Expiration -->
     <!-- Number -->
     <!-- Mandatory -->