diff --git a/packages/kbn-babel-preset/webpack_preset.js b/packages/kbn-babel-preset/webpack_preset.js
index 1c0c189de0642..94c490f1f941e 100644
--- a/packages/kbn-babel-preset/webpack_preset.js
+++ b/packages/kbn-babel-preset/webpack_preset.js
@@ -14,11 +14,15 @@ module.exports = (_, options = {}) => {
       [
         require.resolve('@babel/preset-env'),
         {
-          targets: {
-            esmodules: true,
-          },
+          ...(options.esmodules === false
+            ? {}
+            : {
+                targets: {
+                  esmodules: true,
+                },
+                modules: false,
+              }),
           useBuiltIns: 'entry',
-          modules: false,
           // Please read the explanation for this
           // in node_preset.js
           corejs: '3.21.1',
diff --git a/packages/kbn-optimizer/src/worker/webpack.config.ts b/packages/kbn-optimizer/src/worker/webpack.config.ts
index 422fe12f11b28..8495fa1084391 100644
--- a/packages/kbn-optimizer/src/worker/webpack.config.ts
+++ b/packages/kbn-optimizer/src/worker/webpack.config.ts
@@ -219,8 +219,8 @@ export function getWebpackConfig(bundle: Bundle, bundleRefs: BundleRefs, worker:
               babelrc: false,
               envName: worker.dist ? 'production' : 'development',
               presets: IS_CODE_COVERAGE
-                ? [ISTANBUL_PRESET_PATH, BABEL_PRESET_PATH]
-                : [BABEL_PRESET_PATH],
+                ? [ISTANBUL_PRESET_PATH, [BABEL_PRESET_PATH, { esmodules: false }]]
+                : [[BABEL_PRESET_PATH, { esmodules: false }]],
             },
           },
         },