diff --git a/src/tools/auth0/handlers/customDomains.ts b/src/tools/auth0/handlers/customDomains.ts
index aac2427f..43d204b5 100644
--- a/src/tools/auth0/handlers/customDomains.ts
+++ b/src/tools/auth0/handlers/customDomains.ts
@@ -63,6 +63,7 @@ export default class CustomDomainsHadnler extends DefaultAPIHandler {
         'certificate',
         'created_at',
         'updated_at',
+        'is_default',
       ],
       stripUpdateFields: [
         'status',
@@ -74,6 +75,7 @@ export default class CustomDomainsHadnler extends DefaultAPIHandler {
         'certificate',
         'created_at',
         'updated_at',
+        'is_default',
       ],
     });
   }
diff --git a/test/tools/auth0/handlers/customDomains.test.ts b/test/tools/auth0/handlers/customDomains.test.ts
index a75f534e..06cf474a 100644
--- a/test/tools/auth0/handlers/customDomains.test.ts
+++ b/test/tools/auth0/handlers/customDomains.test.ts
@@ -369,6 +369,7 @@ describe('#customDomains handler', () => {
       primary: true, // should be stripped
       verification: { method: 'cname' }, // should be stripped
       verification_method: 'cname', // should be stripped
+      is_default: true, // should be stripped
       tls_policy: 'recommended', // should NOT be stripped
       domain_metadata: { key: 'value' }, // should NOT be stripped
     };
@@ -405,6 +406,7 @@ describe('#customDomains handler', () => {
     expect(updateCallData).to.not.have.property('primary');
     expect(updateCallData).to.not.have.property('verification');
     expect(updateCallData).to.not.have.property('verification_method');
+    expect(updateCallData).to.not.have.property('is_default');
 
     // Verify that allowed fields are present
     expect(updateCallData).to.have.property('tls_policy', 'recommended');