diff --git a/rollup.config.mjs b/rollup.config.js
similarity index 95%
rename from rollup.config.mjs
rename to rollup.config.js
index 5b6dcb28..0d0039d9 100644
--- a/rollup.config.mjs
+++ b/rollup.config.js
@@ -13,7 +13,7 @@ import {
 
 import path from 'path';
 
-const pkg = importPkg();
+import pkg from './package.json';
 
 const outputDir = 'dist';
 
@@ -139,8 +139,4 @@ function processTemplate(str, args) {
 
     return replacement;
   });
-}
-
-function importPkg() {
-  return JSON.parse(readFileSync('./package.json', { encoding:'utf8' }));
 }
\ No newline at end of file
diff --git a/tasks/build-distro.js b/tasks/build-distro.js
index 7ca55007..8e53c489 100644
--- a/tasks/build-distro.js
+++ b/tasks/build-distro.js
@@ -34,7 +34,7 @@ cp('./assets/bpmn-js.css', dest + '/assets');
 console.log('building pre-packaged distributions');
 
 try {
-  exec('rollup', [ '-c' ], {
+  exec('rollup', [ '-c', '--bundleConfigAsCjs' ], {
     stdio: 'inherit'
   });
 } catch (e) {