diff --git a/lib/webpack/shared.cjs b/lib/webpack/shared.cjs
--- a/lib/webpack/shared.cjs
+++ b/lib/webpack/shared.cjs
@@ -77,6 +77,7 @@
     name: 'browser',
     optimization: {
       minimizer: [new TerserPlugin(), new OptimizeCssAssetsPlugin()],
+      sideEffects: true,
     },
     plugins: [
       ...(baseConfig.plugins ?? []),