diff --git a/packages/plugin-legacy/index.js b/packages/plugin-legacy/index.js
index 1a6394b567daea..1c8020877301e2 100644
--- a/packages/plugin-legacy/index.js
+++ b/packages/plugin-legacy/index.js
@@ -84,7 +84,7 @@ function viteLegacyPlugin(options = {}) {
           modernPolyfills,
           bundle,
           facadeToModernPolyfillMap,
-          config.build.minify
+          config.build
         )
         return
       }
@@ -114,7 +114,7 @@ function viteLegacyPlugin(options = {}) {
           facadeToLegacyPolyfillMap,
           // force using terser for legacy polyfill minification, since esbuild
           // isn't legacy-safe
-          config.build.minify ? 'terser' : false
+          config.build
         )
       }
     }
@@ -382,15 +382,17 @@ function detectPolyfills(code, targets, list) {
  * @param {Set<string>} imports
  * @param {import('rollup').OutputBundle} bundle
  * @param {Map<string, string>} facadeToChunkMap
- * @param {import('vite').BuildOptions['minify']} minify
+ * @param {import('vite').BuildOptions} buildOptions
  */
 async function buildPolyfillChunk(
   name,
   imports,
   bundle,
   facadeToChunkMap,
-  minify
+  buildOptions
 ) {
+  let { minify, assetsDir } = buildOptions
+  minify = minify ? 'terser' : false
   const res = await build({
     // so that everything is resolved from here
     root: __dirname,
@@ -401,6 +403,7 @@ async function buildPolyfillChunk(
       write: false,
       target: false,
       minify,
+      assetsDir,
       rollupOptions: {
         input: {
           [name]: polyfillId