diff --git a/.babelrc b/.babelrc
index eba933fa..89fc7449 100644
--- a/.babelrc
+++ b/.babelrc
@@ -3,9 +3,7 @@
     [
       "@babel/preset-env",
       {
-        "loose": true,
-        "useBuiltIns": "usage",
-        "corejs": 3
+        "loose": true
       }
     ]
   ]
diff --git a/README.md b/README.md
index a05940ec..ad3a9472 100644
--- a/README.md
+++ b/README.md
@@ -3,6 +3,8 @@ this is a fork of https://github.com/Akryum/vue-virtual-scroller:
 * uses @hokify/vue-observe-visibility to fix observer error
 * also includes library updates
 
+* does transpile to es5 (via babel), but does not polyfill (e.g. Map). use core-js to polyfill this if needed (e.g. core-js/modules/es.map) 
+
 To install this fork, use:
 ```
 npm install --save @hokify/vue-virtual-scroller
diff --git a/build/rollup.config.browser.js b/build/rollup.config.browser.js
index 081426e7..0638a434 100644
--- a/build/rollup.config.browser.js
+++ b/build/rollup.config.browser.js
@@ -1,6 +1,5 @@
 import base from './rollup.config.base'
 import { uglify } from 'rollup-plugin-uglify'
-import { minify } from 'uglify-es'
 
 const config = Object.assign({}, base, {
   output: {
@@ -14,6 +13,6 @@ const config = Object.assign({}, base, {
   },
 })
 
-config.plugins.push(uglify({}, minify))
+config.plugins.push(uglify())
 
 export default config
diff --git a/package.json b/package.json
index e0edc2b3..8523c174 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
   "name": "@hokify/vue-virtual-scroller",
   "description": "Smooth scrolling for any amount of data",
-  "version": "1.0.0-rc.9",
+  "version": "1.0.0-rc.10",
   "publishConfig": {
     "access": "public"
   },
@@ -19,7 +19,7 @@
   "module": "dist/vue-virtual-scroller.esm.js",
   "unpkg": "dist/vue-virtual-scroller.min.js",
   "scripts": {
-    "build": "npm run build:browser && npm run build:es && npm run build:umd",
+    "build": "npm run lint && npm run build:browser && npm run build:es && npm run build:umd",
     "build:browser": "rollup --config build/rollup.config.browser.js",
     "build:es": "rollup --config build/rollup.config.es.js",
     "build:umd": "rollup --config build/rollup.config.umd.js",
@@ -70,7 +70,6 @@
     "rollup-plugin-replace": "^2.2.0",
     "rollup-plugin-uglify": "^6.0.2",
     "rollup-plugin-vue": "^5.0.0",
-    "uglify-es": "^3.3.9",
     "vue": "^2.5.17",
     "vue-template-compiler": "2.6.10"
   },