diff --git a/packages/cra-template-typescript/template/src/index.tsx b/packages/cra-template-typescript/template/src/index.tsx
index f5185c1ec7a..6832e7832bb 100644
--- a/packages/cra-template-typescript/template/src/index.tsx
+++ b/packages/cra-template-typescript/template/src/index.tsx
@@ -2,7 +2,6 @@ import React from 'react';
 import ReactDOM from 'react-dom';
 import './index.css';
 import App from './App';
-import * as serviceWorker from './serviceWorker';
 
 ReactDOM.render(
   <React.StrictMode>
@@ -10,8 +9,3 @@ ReactDOM.render(
   </React.StrictMode>,
   document.getElementById('root')
 );
-
-// If you want your app to work offline and load faster, you can change
-// unregister() to register() below. Note this comes with some pitfalls.
-// Learn more about service workers: https://bit.ly/CRA-PWA
-serviceWorker.unregister();
diff --git a/packages/cra-template/template/src/index.js b/packages/cra-template/template/src/index.js
index f5185c1ec7a..6832e7832bb 100644
--- a/packages/cra-template/template/src/index.js
+++ b/packages/cra-template/template/src/index.js
@@ -2,7 +2,6 @@ import React from 'react';
 import ReactDOM from 'react-dom';
 import './index.css';
 import App from './App';
-import * as serviceWorker from './serviceWorker';
 
 ReactDOM.render(
   <React.StrictMode>
@@ -10,8 +9,3 @@ ReactDOM.render(
   </React.StrictMode>,
   document.getElementById('root')
 );
-
-// If you want your app to work offline and load faster, you can change
-// unregister() to register() below. Note this comes with some pitfalls.
-// Learn more about service workers: https://bit.ly/CRA-PWA
-serviceWorker.unregister();
diff --git a/packages/react-dev-utils/FileSizeReporter.js b/packages/react-dev-utils/FileSizeReporter.js
index b2b4cc6904d..80a1b4e7244 100644
--- a/packages/react-dev-utils/FileSizeReporter.js
+++ b/packages/react-dev-utils/FileSizeReporter.js
@@ -16,11 +16,7 @@ var stripAnsi = require('strip-ansi');
 var gzipSize = require('gzip-size').sync;
 
 function canReadAsset(asset) {
-  return (
-    /\.(js|css)$/.test(asset) &&
-    !/service-worker\.js/.test(asset) &&
-    !/precache-manifest\.[0-9a-f]+\.js/.test(asset)
-  );
+  return /\.(js|css)$/.test(asset);
 }
 
 // Prints a detailed summary of build files.
diff --git a/packages/react-dev-utils/WebpackDevServerUtils.js b/packages/react-dev-utils/WebpackDevServerUtils.js
index 07a1ac873ee..8b5952355ce 100644
--- a/packages/react-dev-utils/WebpackDevServerUtils.js
+++ b/packages/react-dev-utils/WebpackDevServerUtils.js
@@ -113,9 +113,9 @@ function createCompiler({
 }) {
   // "Compiler" is a low-level interface to webpack.
   // It lets us listen to some events and provide our own custom messages.
-  let compiler;
+  let masterCompiler;
   try {
-    compiler = webpack(config);
+    masterCompiler = webpack(config);
   } catch (err) {
     console.log(chalk.red('Failed to compile.'));
     console.log();
@@ -128,7 +128,7 @@ function createCompiler({
   // recompiling a bundle. WebpackDevServer takes care to pause serving the
   // bundle, so if you refresh, it'll wait instead of serving the old one.
   // "invalid" is short for "bundle invalidated", it doesn't imply any errors.
-  compiler.hooks.invalid.tap('invalid', () => {
+  masterCompiler.hooks.invalid.tap('invalid', () => {
     if (isInteractive) {
       clearConsole();
     }
@@ -136,39 +136,52 @@ function createCompiler({
   });
 
   let isFirstCompile = true;
-  let tsMessagesPromise;
-  let tsMessagesResolver;
-
-  if (useTypeScript) {
-    compiler.hooks.beforeCompile.tap('beforeCompile', () => {
-      tsMessagesPromise = new Promise(resolve => {
-        tsMessagesResolver = msgs => resolve(msgs);
+  let tsMessagesPromises = [];
+
+  masterCompiler.compilers.forEach((compiler, compilerIndex) => {
+    let tsMessagesResolver;
+    if (useTypeScript) {
+      compiler.hooks.beforeCompile.tap('beforeCompile', () => {
+        tsMessagesPromises[compilerIndex] = new Promise(resolve => {
+          tsMessagesResolver = msgs => resolve(msgs);
+        });
       });
-    });
 
-    forkTsCheckerWebpackPlugin
-      .getCompilerHooks(compiler)
-      .receive.tap('afterTypeScriptCheck', (diagnostics, lints) => {
-        const allMsgs = [...diagnostics, ...lints];
-        const format = message =>
-          `${message.file}\n${typescriptFormatter(message, true)}`;
-
-        tsMessagesResolver({
-          errors: allMsgs.filter(msg => msg.severity === 'error').map(format),
-          warnings: allMsgs
-            .filter(msg => msg.severity === 'warning')
-            .map(format),
+      forkTsCheckerWebpackPlugin
+        .getCompilerHooks(compiler)
+        .receive.tap('afterTypeScriptCheck', (diagnostics, lints) => {
+          const allMsgs = [...diagnostics, ...lints];
+          const format = message =>
+            `${message.file}\n${typescriptFormatter(message, true)}`;
+
+          tsMessagesResolver({
+            errors: allMsgs.filter(msg => msg.severity === 'error').map(format),
+            warnings: allMsgs
+              .filter(msg => msg.severity === 'warning')
+              .map(format),
+          });
         });
-      });
-  }
+    }
+  });
 
   // "done" event fires when webpack has finished recompiling the bundle.
   // Whether or not you have warnings or errors, you will get this event.
-  compiler.hooks.done.tap('done', async stats => {
+  masterCompiler.hooks.done.tap('done', async stats => {
     if (isInteractive) {
       clearConsole();
     }
 
+    stats.compilation = {
+      errors: stats.stats.reduce(
+        (previousErrors, s) => [...previousErrors, ...s.compilation.errors],
+        []
+      ),
+      warnings: stats.stats.reduce(
+        (previousErrors, s) => [...previousErrors, ...s.compilation.warnings],
+        []
+      ),
+    };
+
     // We have switched off the default webpack output in WebpackDevServer
     // options so we are going to "massage" the warnings and errors and present
     // them in a readable focused way.
@@ -189,7 +202,14 @@ function createCompiler({
         );
       }, 100);
 
-      const messages = await tsMessagesPromise;
+      const masterMessages = await Promise.all(tsMessagesPromises);
+      const messages = masterMessages.reduce(
+        (previousMessages, currentMessages) => ({
+          errors: [...previousMessages.errors, ...currentMessages.errors],
+          warnings: [...previousMessages.warnings, ...currentMessages.warnings],
+        }),
+        { errors: [], warnings: [] }
+      );
       clearTimeout(delayedMsg);
       if (tscCompileOnError) {
         statsData.warnings.push(...messages.errors);
@@ -269,12 +289,12 @@ function createCompiler({
     arg => arg.indexOf('--smoke-test') > -1
   );
   if (isSmokeTest) {
-    compiler.hooks.failed.tap('smokeTest', async () => {
-      await tsMessagesPromise;
+    masterCompiler.hooks.failed.tap('smokeTest', async () => {
+      await Promise.all(tsMessagesPromises);
       process.exit(1);
     });
-    compiler.hooks.done.tap('smokeTest', async stats => {
-      await tsMessagesPromise;
+    masterCompiler.hooks.done.tap('smokeTest', async stats => {
+      await Promise.all(tsMessagesPromises);
       if (stats.hasErrors() || stats.hasWarnings()) {
         process.exit(1);
       } else {
@@ -283,7 +303,7 @@ function createCompiler({
     });
   }
 
-  return compiler;
+  return masterCompiler;
 }
 
 function resolveLoopback(proxy) {
diff --git a/packages/react-dev-utils/package.json b/packages/react-dev-utils/package.json
index 36ea5b34047..12181108bb1 100644
--- a/packages/react-dev-utils/package.json
+++ b/packages/react-dev-utils/package.json
@@ -1,6 +1,6 @@
 {
-  "name": "react-dev-utils",
-  "version": "10.2.1",
+  "name": "@ouihelp/react-dev-utils",
+  "version": "10020001.0.2",
   "description": "webpack utilities used by Create React App",
   "repository": {
     "type": "git",
diff --git a/packages/react-scripts/config/paths.js b/packages/react-scripts/config/paths.js
index 11d81b7f5a7..4fa29ad33a6 100644
--- a/packages/react-scripts/config/paths.js
+++ b/packages/react-scripts/config/paths.js
@@ -64,6 +64,7 @@ module.exports = {
   appPublic: resolveApp('public'),
   appHtml: resolveApp('public/index.html'),
   appIndexJs: resolveModule(resolveApp, 'src/index'),
+  appServiceWorkerJs: resolveModule(resolveApp, 'src/service-worker.entry'),
   appPackageJson: resolveApp('package.json'),
   appSrc: resolveApp('src'),
   appTsConfig: resolveApp('tsconfig.json'),
@@ -86,6 +87,7 @@ module.exports = {
   appPublic: resolveApp('public'),
   appHtml: resolveApp('public/index.html'),
   appIndexJs: resolveModule(resolveApp, 'src/index'),
+  appServiceWorkerJs: resolveModule(resolveApp, 'src/service-worker.entry'),
   appPackageJson: resolveApp('package.json'),
   appSrc: resolveApp('src'),
   appTsConfig: resolveApp('tsconfig.json'),
@@ -121,6 +123,10 @@ if (
     appPublic: resolveOwn(`${templatePath}/public`),
     appHtml: resolveOwn(`${templatePath}/public/index.html`),
     appIndexJs: resolveModule(resolveOwn, `${templatePath}/src/index`),
+    appServiceWorkerJs: resolveModule(
+      resolveOwn,
+      `${templatePath}/src/service-worker.entry`
+    ),
     appPackageJson: resolveOwn('package.json'),
     appSrc: resolveOwn(`${templatePath}/src`),
     appTsConfig: resolveOwn(`${templatePath}/tsconfig.json`),
diff --git a/packages/react-scripts/config/webpack.config.js b/packages/react-scripts/config/webpack.config.js
index 25840d91148..b6153d06212 100644
--- a/packages/react-scripts/config/webpack.config.js
+++ b/packages/react-scripts/config/webpack.config.js
@@ -22,7 +22,6 @@ const OptimizeCSSAssetsPlugin = require('optimize-css-assets-webpack-plugin');
 const safePostCssParser = require('postcss-safe-parser');
 const ManifestPlugin = require('webpack-manifest-plugin');
 const InterpolateHtmlPlugin = require('react-dev-utils/InterpolateHtmlPlugin');
-const WorkboxWebpackPlugin = require('workbox-webpack-plugin');
 const WatchMissingNodeModulesPlugin = require('react-dev-utils/WatchMissingNodeModulesPlugin');
 const ModuleScopePlugin = require('react-dev-utils/ModuleScopePlugin');
 const getCSSModuleLocalIdent = require('react-dev-utils/getCSSModuleLocalIdent');
@@ -138,7 +137,7 @@ module.exports = function(webpackEnv) {
     return loaders;
   };
 
-  return {
+  const originalConfig = {
     mode: isEnvProduction ? 'production' : isEnvDevelopment && 'development',
     // Stop compilation early in production
     bail: isEnvProduction,
@@ -246,6 +245,9 @@ module.exports = function(webpackEnv) {
             },
           },
           sourceMap: shouldUseSourceMap,
+          // We cheat on this one to avoid a bug on CI providers advertising
+          // overly high number of CPUs.
+          parallel: 4,
         }),
         // This is only used in production mode
         new OptimizeCSSAssetsPlugin({
@@ -654,24 +656,6 @@ module.exports = function(webpackEnv) {
       // https://github.com/jmblog/how-to-optimize-momentjs-with-webpack
       // You can remove this if you don't use Moment.js:
       new webpack.IgnorePlugin(/^\.\/locale$/, /moment$/),
-      // Generate a service worker script that will precache, and keep up to date,
-      // the HTML & assets that are part of the webpack build.
-      isEnvProduction &&
-        new WorkboxWebpackPlugin.GenerateSW({
-          clientsClaim: true,
-          exclude: [/\.map$/, /asset-manifest\.json$/],
-          importWorkboxFrom: 'cdn',
-          navigateFallback: paths.publicUrlOrPath + 'index.html',
-          navigateFallbackBlacklist: [
-            // Exclude URLs starting with /_, as they're likely an API call
-            new RegExp('^/_'),
-            // Exclude any URLs whose last part seems to be a file extension
-            // as they're likely a resource and not a SPA route.
-            // URLs containing a "?" character won't be blacklisted as they're likely
-            // a route with query params (e.g. auth callbacks).
-            new RegExp('/[^/?]+\\.[^/]+$'),
-          ],
-        }),
       // TypeScript type checking
       useTypeScript &&
         new ForkTsCheckerWebpackPlugin({
@@ -716,4 +700,59 @@ module.exports = function(webpackEnv) {
     // our own hints via the FileSizeReporter
     performance: false,
   };
+
+  const serviceWorkerConfig = {
+    target: 'webworker',
+    mode: originalConfig.mode,
+    bail: originalConfig.bail,
+    devtool: originalConfig.devtool,
+    entry: { 'service-worker': paths.appServiceWorkerJs },
+    output: {
+      path: originalConfig.output.path,
+      pathinfo: originalConfig.output.pathinfo,
+      filename: 'sw.js',
+      publicPath: originalConfig.output.publicPath,
+      devtoolModuleFilenameTemplate:
+        originalConfig.output.devtoolModuleFilenameTemplate,
+    },
+    optimization: {
+      minimize: originalConfig.optimization.minimize,
+      minimizer: originalConfig.optimization.minimizer,
+    },
+    resolve: originalConfig.resolve,
+    resolveLoader: originalConfig.resolveLoader,
+    module: originalConfig.module,
+    plugins: [
+      new webpack.DefinePlugin(env.stringified),
+      useTypeScript &&
+        new ForkTsCheckerWebpackPlugin({
+          typescript: resolve.sync('typescript', {
+            basedir: paths.appNodeModules,
+          }),
+          async: isEnvDevelopment,
+          useTypescriptIncrementalApi: true,
+          checkSyntacticErrors: true,
+          resolveModuleNameModule: process.versions.pnp
+            ? `${__dirname}/pnpTs.js`
+            : undefined,
+          resolveTypeReferenceDirectiveModule: process.versions.pnp
+            ? `${__dirname}/pnpTs.js`
+            : undefined,
+          tsconfig: paths.appTsConfig,
+          reportFiles: [
+            '**',
+            '!**/__tests__/**',
+            '!**/?(*.)(spec|test).*',
+            '!**/src/setupProxy.*',
+            '!**/src/setupTests.*',
+          ],
+          watch: paths.appSrc,
+          silent: true,
+          // The formatter is invoked directly in WebpackDevServerUtils during development
+          formatter: isEnvProduction ? typescriptFormatter : undefined,
+        }),
+    ].filter(Boolean),
+  };
+
+  return [originalConfig, serviceWorkerConfig];
 };
diff --git a/packages/react-scripts/package.json b/packages/react-scripts/package.json
index 63e7faf390c..7a265754804 100644
--- a/packages/react-scripts/package.json
+++ b/packages/react-scripts/package.json
@@ -1,6 +1,6 @@
 {
-  "name": "react-scripts",
-  "version": "3.4.1",
+  "name": "@ouihelp/react-scripts",
+  "version": "3004001.0.4",
   "description": "Configuration and scripts for Create React App.",
   "repository": {
     "type": "git",
@@ -29,6 +29,7 @@
   "types": "./lib/react-app.d.ts",
   "dependencies": {
     "@babel/core": "7.9.0",
+    "@ouihelp/react-dev-utils": "10020001.0.2",
     "@svgr/webpack": "4.3.3",
     "@typescript-eslint/eslint-plugin": "^2.10.0",
     "@typescript-eslint/parser": "^2.10.0",
diff --git a/packages/react-scripts/scripts/build.js b/packages/react-scripts/scripts/build.js
index fa30fb09a3f..27aa23e54fc 100644
--- a/packages/react-scripts/scripts/build.js
+++ b/packages/react-scripts/scripts/build.js
@@ -40,7 +40,7 @@ const paths = require('../config/paths');
 const checkRequiredFiles = require('react-dev-utils/checkRequiredFiles');
 const formatWebpackMessages = require('react-dev-utils/formatWebpackMessages');
 const printHostingInstructions = require('react-dev-utils/printHostingInstructions');
-const FileSizeReporter = require('react-dev-utils/FileSizeReporter');
+const FileSizeReporter = require('@ouihelp/react-dev-utils/FileSizeReporter');
 const printBuildError = require('react-dev-utils/printBuildError');
 
 const measureFileSizesBeforeBuild =
@@ -111,7 +111,7 @@ checkBrowsers(paths.appPath, isInteractive)
 
       const appPackage = require(paths.appPackageJson);
       const publicUrl = paths.publicUrlOrPath;
-      const publicPath = config.output.publicPath;
+      const publicPath = config[0].output.publicPath;
       const buildFolder = path.relative(process.cwd(), paths.appBuild);
       printHostingInstructions(
         appPackage,
diff --git a/packages/react-scripts/scripts/start.js b/packages/react-scripts/scripts/start.js
index 2568ab36db1..86d6253c544 100644
--- a/packages/react-scripts/scripts/start.js
+++ b/packages/react-scripts/scripts/start.js
@@ -42,7 +42,7 @@ const {
   createCompiler,
   prepareProxy,
   prepareUrls,
-} = require('react-dev-utils/WebpackDevServerUtils');
+} = require('@ouihelp/react-dev-utils/WebpackDevServerUtils');
 const openBrowser = require('react-dev-utils/openBrowser');
 const paths = require('../config/paths');
 const configFactory = require('../config/webpack.config');
diff --git a/packages/react-scripts/scripts/utils/verifyTypeScriptSetup.js b/packages/react-scripts/scripts/utils/verifyTypeScriptSetup.js
index ebd93d7b667..b072e5a3e57 100644
--- a/packages/react-scripts/scripts/utils/verifyTypeScriptSetup.js
+++ b/packages/react-scripts/scripts/utils/verifyTypeScriptSetup.js
@@ -256,7 +256,7 @@ function verifyTypeScriptSetup() {
   if (!fs.existsSync(paths.appTypeDeclarations)) {
     fs.writeFileSync(
       paths.appTypeDeclarations,
-      `/// <reference types="react-scripts" />${os.EOL}`
+      `/// <reference types="@ouihelp/react-scripts" />${os.EOL}`
     );
   }
 }