diff --git a/src/v1/essential_contacts_service_client.ts b/src/v1/essential_contacts_service_client.ts
index eb141a3..511d505 100644
--- a/src/v1/essential_contacts_service_client.ts
+++ b/src/v1/essential_contacts_service_client.ts
@@ -132,6 +132,12 @@ export class EssentialContactsServiceClient {
     // Save the auth object to the client, for use by other methods.
     this.auth = this._gaxGrpc.auth as gax.GoogleAuth;
 
+    // Set useJWTAccessWithScope on the auth object.
+    this.auth.useJWTAccessWithScope = true;
+
+    // Set defaultServicePath on the auth object.
+    this.auth.defaultServicePath = staticMembers.servicePath;
+
     // Set the default scopes in auth client if needed.
     if (servicePath === staticMembers.servicePath) {
       this.auth.defaultScopes = staticMembers.scopes;