diff --git a/packages/google-cloud-bigquery-datatransfer/src/v1/data_transfer_service_client.ts b/packages/google-cloud-bigquery-datatransfer/src/v1/data_transfer_service_client.ts
index 1458c5f3e8c..73331b026c0 100644
--- a/packages/google-cloud-bigquery-datatransfer/src/v1/data_transfer_service_client.ts
+++ b/packages/google-cloud-bigquery-datatransfer/src/v1/data_transfer_service_client.ts
@@ -134,6 +134,12 @@ export class DataTransferServiceClient {
     // 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;