diff --git a/packages/core/src/server/build/fleck.webpack.config.js b/packages/core/src/server/build/fleck.webpack.config.js
index 2872f80..3768deb 100644
--- a/packages/core/src/server/build/fleck.webpack.config.js
+++ b/packages/core/src/server/build/fleck.webpack.config.js
@@ -5,18 +5,23 @@ const {
   join,
 } = require('path');
 
+const babelmerge = require('babel-merge');
 const CopyPlugin = require('copy-webpack-plugin');
 const glob = require('glob');
 const ESLintPlugin = require('eslint-webpack-plugin');
 
+const D = require('../../debug');
 const R = require('../../require');
-const {defaultConfig, externals} = require('../webpack');
+const {defaultConfig, externals, regexFromExtensions} = require('../webpack');
 const eslintConfigFn = require('./default.eslint.config');
 
 const {
   FLECKS_CORE_ROOT = process.cwd(),
 } = process.env;
 
+const debug = D('@flecks/core/server/build/fleck.webpack.config.js');
+const debugSilly = debug.extend('silly');
+
 const source = join(FLECKS_CORE_ROOT, 'src');
 const tests = join(FLECKS_CORE_ROOT, 'test');
 
@@ -97,6 +102,48 @@ module.exports = (env, argv, flecks) => {
     },
     target: 'node',
   });
+  const merging = [
+    {
+      plugins: ['@babel/plugin-syntax-dynamic-import'],
+      presets: [
+        [
+          '@babel/preset-env',
+          {
+            shippedProposals: true,
+            targets: {
+              esmodules: true,
+              node: 'current',
+            },
+          },
+        ],
+      ],
+    },
+  ];
+  if (flecks) {
+    merging.push({configFile: flecks.buildConfig('babel.config.js')});
+    const rcBabel = flecks.babel();
+    debugSilly('.flecksrc: babel: %j', rcBabel);
+    merging.push(...rcBabel.map(([, babel]) => babel));
+  }
+  const babelConfig = babelmerge.all(merging);
+  const extensionsRegex = regexFromExtensions(config.resolve.extensions);
+  config.module.rules.push(
+    {
+      include: [source, tests],
+      test: extensionsRegex,
+      use: [
+        {
+          loader: 'babel-loader',
+          options: {
+            cacheDirectory: true,
+            babelrc: false,
+            configFile: false,
+            ...babelConfig,
+          },
+        },
+      ],
+    },
+  );
   const eslint = eslintConfigFn(flecks);
   eslint.settings['import/resolver'].webpack = {
     config: {
diff --git a/packages/core/src/server/webpack.js b/packages/core/src/server/webpack.js
index eb5dbad..f1dbe20 100644
--- a/packages/core/src/server/webpack.js
+++ b/packages/core/src/server/webpack.js
@@ -1,22 +1,14 @@
 const {chmod} = require('fs');
 const {join} = require('path');
 
-const babelmerge = require('babel-merge');
 const CopyPlugin = require('copy-webpack-plugin');
 const webpack = require('webpack');
 const nodeExternals = require('webpack-node-externals');
 
-const D = require('../debug');
-
 const {
   FLECKS_CORE_ROOT = process.cwd(),
 } = process.env;
 
-const debug = D('@flecks/core/server/webpack');
-const debugSilly = debug.extend('silly');
-const source = join(FLECKS_CORE_ROOT, 'src');
-const tests = join(FLECKS_CORE_ROOT, 'test');
-
 exports.banner = (options) => (
   new webpack.BannerPlugin({
     entryOnly: true,
@@ -29,31 +21,9 @@ exports.copy = (options) => (new CopyPlugin(options));
 
 exports.defaultConfig = (flecks, specializedConfig) => {
   const extensions = ['.mjs', '.js', '.json', '.wasm'];
-  const merging = [
-    {
-      plugins: ['@babel/plugin-syntax-dynamic-import'],
-      presets: [
-        [
-          '@babel/preset-env',
-          {
-            shippedProposals: true,
-            targets: {
-              esmodules: true,
-              node: 'current',
-            },
-          },
-        ],
-      ],
-    },
-  ];
   if (flecks) {
     extensions.push(...flecks.exts());
-    merging.push({configFile: flecks.buildConfig('babel.config.js')});
-    const rcBabel = flecks.babel();
-    debugSilly('.flecksrc: babel: %j', rcBabel);
-    merging.push(...rcBabel.map(([, babel]) => babel));
   }
-  const babelConfig = babelmerge.all(merging);
   const extensionsRegex = exports.regexFromExtensions(extensions);
   const defaults = {
     context: FLECKS_CORE_ROOT,
@@ -66,21 +36,6 @@ exports.defaultConfig = (flecks, specializedConfig) => {
           test: extensionsRegex,
           use: ['source-map-loader'],
         },
-        {
-          include: [source, tests],
-          test: extensionsRegex,
-          use: [
-            {
-              loader: 'babel-loader',
-              options: {
-                cacheDirectory: true,
-                babelrc: false,
-                configFile: false,
-                ...babelConfig,
-              },
-            },
-          ],
-        },
       ],
     },
     output: {