diff --git a/tools/build_cdn.js b/tools/build_cdn.js
index c240508d9a..6400f60afc 100644
--- a/tools/build_cdn.js
+++ b/tools/build_cdn.js
@@ -125,7 +125,7 @@ async function installLanguages(languages, options) {
 
   await Promise.all(
     languages.filter((l) => l.third_party)
-      .map(buildDistributable)
+      .map((lang) => buildDistributable(lang, options))
   );
 
   log("");
@@ -148,13 +148,16 @@ function installStyles() {
   });
 }
 
-async function buildDistributable(language) {
+async function buildDistributable(language, options) {
   const filename = `${language.name}.min.js`;
 
   const distDir = path.join(language.moduleDir, "dist");
   log(`Building ${distDir}/${filename}.`);
   await fs.mkdir(distDir, { recursive: true });
   await fs.writeFile(path.join(language.moduleDir, "dist", filename), language.minified);
+  if (options.esm) {
+    await fs.writeFile(path.join(language.moduleDir, "dist", filename.replace(".min.js",".es.min.js")), language.minifiedESM);
+  }
 }
 
 async function buildCDNLanguage(language, options) {
diff --git a/tools/lib/language.js b/tools/lib/language.js
index ced7e60926..7b026fb8e2 100644
--- a/tools/lib/language.js
+++ b/tools/lib/language.js
@@ -85,20 +85,22 @@ class Language {
 
 
 async function compileLanguage (language, options) {
-  const EXPORT_REGEX = /export default (.*);/;
+  const IIFE_HEADER_REGEX = /^(var hljsGrammar = )?\(function \(\)/;
 
   // TODO: cant we use the source we already have?
-  const input = { ...build_config.rollup.browser.input, input: language.path };
-  const output = { ...build_config.rollup.browser.output,  name: `dummyName`, file: "out.js" };
+  const input = { ...build_config.rollup.browser_iife.input, input: language.path };
+  const output = { ...build_config.rollup.browser_iife.output, name: `hljsGrammar`, file: "out.js" };
+  output.footer = null;
   
-  const esm = await rollupCode(input, output);
-  const iife = `hljs.registerLanguage('${language.name}', function (){"use strict";` + esm.replace(EXPORT_REGEX, 'return $1') + '})';
+  const data = await rollupCode(input, output);
+  const iife = data.replace(IIFE_HEADER_REGEX, `hljs.registerLanguage('${language.name}', function ()`);
+  const esm = `${data};\nexport default hljsGrammar;`;
 
   language.module = iife;
   const miniESM = await Terser.minify(esm, options.terser);
   const miniIIFE = await Terser.minify(iife, options.terser);
-  language.minified = miniIIFE.code || iife;
-  language.minifiedESM = miniESM.code || esm;
+  language.minified = miniIIFE.code;
+  language.minifiedESM = miniESM.code;
 }
 
 async function getLanguages() {