diff --git a/README.md b/README.md
index 51eb814..1ab5943 100644
--- a/README.md
+++ b/README.md
@@ -96,6 +96,13 @@ for an easy way to externalize all node modules.
 
 ### Source Maps
 Yes using `devtool: 'source-map'` works, include `require('source-map-support').install();` you'll have pretty stacktraces.
+
+### Loading additional modules before the lambda function module
+If you need to load modules before your lambda function module is loaded,
+you can specify those modules with entry option in your webpack config.
+For example if you need to load the babel-polyfill, you can do that
+by adding `entry: ['babel-polyfill']` to your webpack config.
+This will first load the babel-polyfill module and then your lambda function module.
  
 ### Improving deploy performance
   
diff --git a/index.js b/index.js
index e5a6269..aef6db0 100644
--- a/index.js
+++ b/index.js
@@ -75,10 +75,15 @@ module.exports = function getPlugin(S) {
           const webpackConfig = Object.assign({}, config.webpackConfig);
           const handlerName = func.getHandler().split('.')[0];
           const handlerFileName = `${handlerName}.${config.handlerExt}`;
+          const handlerEntryPath = `./${handlerFileName}`;
 
           // override entry and output
           webpackConfig.context = path.dirname(func.getFilePath());
-          webpackConfig.entry = `./${handlerFileName}`;
+          if (Array.isArray(webpackConfig.entry)) {
+            webpackConfig.entry.push(handlerEntryPath);
+          } else {
+            webpackConfig.entry = handlerEntryPath;
+          }
           webpackConfig.output = {
             libraryTarget: 'commonjs',
             path: optimizedPath,