diff --git a/packages/kbn-optimizer/src/worker/webpack.config.ts b/packages/kbn-optimizer/src/worker/webpack.config.ts
index bb58bd0a3f00..9010746f9fde 100644
--- a/packages/kbn-optimizer/src/worker/webpack.config.ts
+++ b/packages/kbn-optimizer/src/worker/webpack.config.ts
@@ -289,6 +289,7 @@ export function getWebpackConfig(bundle: Bundle, worker: WorkerConfig) {
 
     resolve: {
       extensions: ['.js', '.ts', '.tsx', '.json'],
+      mainFields: ['browser', 'main'],
       alias: {
         tinymath: require.resolve('tinymath/lib/tinymath.es5.js'),
       },