diff --git a/scripts/build.sh b/scripts/build.sh
index 1f37445d86c..fe5b4e53775 100755
--- a/scripts/build.sh
+++ b/scripts/build.sh
@@ -15,7 +15,7 @@ echo 'Done.'
 echo ''
 
 echo 'Build ES modules...'
-NODE_ENV=es babel src --out-dir es --ignore 'src/**/*/fixtures,src/**/*.spec.js'
+NODE_ENV=es babel src --out-dir es --ignore 'src/**/*.spec.js'
 echo 'Done.'
 echo ''
 
diff --git a/scripts/rollup.config.esm.js b/scripts/rollup.config.esm.js
deleted file mode 100644
index 8d398854917..00000000000
--- a/scripts/rollup.config.esm.js
+++ /dev/null
@@ -1,34 +0,0 @@
-import fs from 'fs'
-import path from 'path'
-import babel from 'rollup-plugin-babel'
-import resolve from 'rollup-plugin-node-resolve'
-import commonjs from 'rollup-plugin-commonjs'
-import css from 'rollup-plugin-css-porter'
-import { name, dependencies } from '../package.json'
-
-const base = path.resolve(__dirname, '..')
-const src = path.resolve(base, 'src')
-const dist = path.resolve(base, 'dist')
-
-// Ensure dist directory exists
-if (!fs.existsSync(dist)) {
-  fs.mkdirSync(dist)
-}
-
-export default {
-  input: path.resolve(src, 'index.js'),
-  external: Object.keys(dependencies),
-  plugins: [
-    css({ dest: path.resolve(dist, `${name}.css`) }),
-    resolve({ external: ['vue'] }),
-    commonjs(),
-    babel()
-  ],
-  output: [
-    {
-      format: 'es',
-      file: path.resolve(dist, `${name}.esm.js`),
-      sourcemap: true
-    }
-  ]
-}
diff --git a/scripts/rollup.config.js b/scripts/rollup.config.js
index 18d6ae82999..2b79ab515e5 100644
--- a/scripts/rollup.config.js
+++ b/scripts/rollup.config.js
@@ -14,13 +14,14 @@ const externals = ['vue', ...Object.keys(dependencies)]
 
 // Libs in `external` will not be bundled to dist,
 // since they are expected to be provided later.
-// We want to include some of them in the build, so we exclude it here.
+// In some cases, wee want to include some of them in the build, so we
+// exclude the external here.
 const externalExcludes = ['popper.js', 'vue-functional-data-merge']
 
 // The base rollup configuration
 const baseConfig = {
   input: path.resolve(src, 'index.js'),
-  external: Object.keys(dependencies),
+  external: externals,
   plugins: [resolve({ external: ['vue'] }), commonjs(), babel({ exclude: 'node_modules/**' })]
 }
 
@@ -57,10 +58,9 @@ export default [
     }
   },
 
-  // ES
+  // ESM
   {
     ...baseConfig,
-    external: ['vue'],
     output: {
       format: 'es',
       file: path.resolve(dist, `${name}.esm.js`),