diff --git a/packages/google-cloud-binaryauthorization/src/v1beta1/binauthz_management_service_v1_beta1_client.ts b/packages/google-cloud-binaryauthorization/src/v1beta1/binauthz_management_service_v1_beta1_client.ts
index 9a749c4dfc8..ac21acf2e51 100644
--- a/packages/google-cloud-binaryauthorization/src/v1beta1/binauthz_management_service_v1_beta1_client.ts
+++ b/packages/google-cloud-binaryauthorization/src/v1beta1/binauthz_management_service_v1_beta1_client.ts
@@ -147,6 +147,8 @@ export class BinauthzManagementServiceV1Beta1Client {
     }
     if (!opts.fallback) {
       clientHeader.push(`grpc/${this._gaxGrpc.grpcVersion}`);
+    } else if (opts.fallback === 'rest') {
+      clientHeader.push(`rest/${this._gaxGrpc.grpcVersion}`);
     }
     if (opts.libName && opts.libVersion) {
       clientHeader.push(`${opts.libName}/${opts.libVersion}`);