diff --git a/packages/react-scripts/bin/react-scripts.js b/packages/react-scripts/bin/react-scripts.js
index 8a1175c99eae8592ec7ad1ff7adaf8a2c3933b89..7bf1e7503e281c2605fb13ea3c7b43b91caeac2b 100755
--- a/packages/react-scripts/bin/react-scripts.js
+++ b/packages/react-scripts/bin/react-scripts.js
@@ -10,16 +10,16 @@
 
 'use strict';
 
-var spawn = require('cross-spawn');
-var script = process.argv[2];
-var args = process.argv.slice(3);
+const spawn = require('cross-spawn');
+const script = process.argv[2];
+const args = process.argv.slice(3);
 
 switch (script) {
   case 'build':
   case 'eject':
   case 'start':
-  case 'test':
-    var result = spawn.sync(
+  case 'test': {
+    const result = spawn.sync(
       'node',
       [require.resolve('../scripts/' + script)].concat(args),
       { stdio: 'inherit' }
@@ -42,6 +42,7 @@ switch (script) {
     }
     process.exit(result.status);
     break;
+  }
   default:
     console.log('Unknown script "' + script + '".');
     console.log('Perhaps you need to update react-scripts?');
diff --git a/packages/react-scripts/config/env.js b/packages/react-scripts/config/env.js
index 6d14719d6ad47980cf79012d14fe5065390e2c16..4213adf69a211bfc183ccb3b7d948a6715cc5194 100644
--- a/packages/react-scripts/config/env.js
+++ b/packages/react-scripts/config/env.js
@@ -10,10 +10,10 @@
 // @remove-on-eject-end
 'use strict';
 
-var fs = require('fs');
-var paths = require('./paths');
+const fs = require('fs');
+const paths = require('./paths');
 
-var NODE_ENV = process.env.NODE_ENV;
+const NODE_ENV = process.env.NODE_ENV;
 if (!NODE_ENV) {
   throw new Error(
     'The NODE_ENV environment variable is required but was not specified.'
@@ -22,9 +22,9 @@ if (!NODE_ENV) {
 
 // https://github.com/bkeepers/dotenv#what-other-env-files-can-i-use
 var dotenvFiles = [
-  paths.dotenv + '.' + NODE_ENV + '.local',
-  paths.dotenv + '.' + NODE_ENV,
-  paths.dotenv + '.local',
+  `${paths.dotenv}.${NODE_ENV}.local`,
+  `${paths.dotenv}.${NODE_ENV}`,
+  `${paths.dotenv}.local`,
   paths.dotenv,
 ];
 // Load environment variables from .env* files. Suppress warnings using silent
diff --git a/packages/react-scripts/config/paths.js b/packages/react-scripts/config/paths.js
index 915b1a83865b1e108bf6517adc2f3e7d3d20a56e..0afef5e93d54f9fc5df1976bae094cf2270df2d1 100644
--- a/packages/react-scripts/config/paths.js
+++ b/packages/react-scripts/config/paths.js
@@ -17,9 +17,7 @@ const url = require('url');
 // Make sure any symlinks in the project folder are resolved:
 // https://github.com/facebookincubator/create-react-app/issues/637
 const appDirectory = fs.realpathSync(process.cwd());
-function resolveApp(relativePath) {
-  return path.resolve(appDirectory, relativePath);
-}
+const resolveApp = (relativePath) => path.resolve(appDirectory, relativePath);
 
 // We support resolving modules according to `NODE_PATH`.
 // This lets you use absolute paths in imports inside large monorepos:
@@ -55,9 +53,7 @@ function ensureSlash(path, needsSlash) {
   }
 }
 
-function getPublicUrl(appPackageJson) {
-  return envPublicUrl || require(appPackageJson).homepage;
-}
+const getPublicUrl = (appPackageJson) => envPublicUrl || require(appPackageJson).homepage;
 
 // We use `PUBLIC_URL` environment variable or "homepage" field to infer
 // "public path" at which the app is served.
@@ -90,9 +86,7 @@ module.exports = {
 };
 
 // @remove-on-eject-begin
-function resolveOwn(relativePath) {
-  return path.resolve(__dirname, '..', relativePath);
-}
+const resolveOwn = (relativePath) => path.resolve(__dirname, '..', relativePath);
 
 // config before eject: we're in ./node_modules/react-scripts/config/
 module.exports = {