diff --git a/packages/ses/scripts/bundle.js b/packages/ses/scripts/bundle.js
index 3880ec1455..e132a57c13 100644
--- a/packages/ses/scripts/bundle.js
+++ b/packages/ses/scripts/bundle.js
@@ -5,6 +5,7 @@ import fs from 'fs';
 import { makeBundle } from '@endo/compartment-mapper/bundle.js';
 import { minify } from 'terser';
 import { fileURLToPath, pathToFileURL } from 'url';
+import { getEnvironmentOption as getenv } from '@endo/env-options';
 import { hermesTransforms } from './hermesTransforms.js';
 
 const resolve = (rel, abs) => fileURLToPath(new URL(rel, abs).toString());
@@ -102,7 +103,8 @@ const writeBundle = async ({ buildType } = {}) => {
 };
 
 const main = async () => {
-  await writeBundle({ buildType: process.env.SES_BUILD_TYPE || 'vanilla' });
+  const buildType = getenv('SES_BUILD_TYPE', 'vanilla');
+  await writeBundle({ buildType });
 };
 
 main().catch(err => {