diff --git a/bin/eslint-ignore-errors.js b/bin/eslint-ignore-errors.js
index 3d71b833..643d3f77 100755
--- a/bin/eslint-ignore-errors.js
+++ b/bin/eslint-ignore-errors.js
@@ -11,22 +11,22 @@ const fs = require('fs')
 const execFile = require('child_process').execFile
 
 execFile('eslint', ['--format', 'json', process.argv[2]], (error, stdout) => {
-  JSON.parse(stdout).forEach(result => {
+  for (const result of JSON.parse(stdout)) {
     const filename = result.filePath
     const jsLines = fs.readFileSync(filename, 'utf8').split('\n')
     const offensesByLine = {}
     let addedLines = 0
 
     // Produces {47: ['github/no-d-none', 'github/no-blur'], 83: ['github/no-blur']}
-    result.messages.forEach(message => {
+    for (const message of result.messages) {
       if (offensesByLine[message.line]) {
         offensesByLine[message.line].push(message.ruleId)
       } else {
         offensesByLine[message.line] = [message.ruleId]
       }
-    })
+    }
 
-    Object.keys(offensesByLine).forEach(line => {
+    for (const line of Object.keys(offensesByLine)) {
       const lineIndex = line - 1 + addedLines
       const previousLine = jsLines[lineIndex - 1]
       const ruleIds = offensesByLine[line].join(', ')
@@ -37,12 +37,12 @@ execFile('eslint', ['--format', 'json', process.argv[2]], (error, stdout) => {
         jsLines.splice(lineIndex, 0, `${leftPad}/* eslint-disable-next-line ${ruleIds} */`)
       }
       addedLines += 1
-    })
+    }
 
     if (result.messages.length !== 0) {
       fs.writeFileSync(filename, jsLines.join('\n'), 'utf8')
     }
-  })
+  }
 })
 
 function isDisableComment(line) {
diff --git a/bin/npm-check-github-package-requirements.js b/bin/npm-check-github-package-requirements.js
index c55b0d8d..88c9aa41 100755
--- a/bin/npm-check-github-package-requirements.js
+++ b/bin/npm-check-github-package-requirements.js
@@ -10,7 +10,7 @@ function check(name, callback) {
 
 function run() {
   process.stdout.write(`1..${checks.length}\n`)
-  checks.forEach(([count, name, callback]) => {
+  for (const [count, name, callback] of checks) {
     Promise.resolve()
       .then(callback)
       .then(() => {
@@ -19,7 +19,7 @@ function run() {
       .catch(error => {
         process.stdout.write(`not ok ${count} - ${name}\n  ${error}\n`)
       })
-  })
+  }
 }
 
 const packageRoot = process.argv[2]
diff --git a/lib/configs/app.js b/lib/configs/app.js
index fa41d90c..92a4fc6d 100644
--- a/lib/configs/app.js
+++ b/lib/configs/app.js
@@ -7,5 +7,5 @@ module.exports = {
     'github/no-dataset': 'error',
     'github/no-then': 'error'
   },
-  extends: [require.resolve('./recommended'), require.resolve('./es6'), require.resolve('./browser')]
+  extends: [require.resolve('./recommended'), require.resolve('./browser')]
 }
diff --git a/lib/configs/es6.js b/lib/configs/es6.js
deleted file mode 100644
index a2ec3ebd..00000000
--- a/lib/configs/es6.js
+++ /dev/null
@@ -1,51 +0,0 @@
-module.exports = {
-  parserOptions: {
-    ecmaFeatures: {
-      ecmaVersion: 6
-    },
-    sourceType: 'module'
-  },
-  env: {
-    es6: true
-  },
-  plugins: ['github', 'import'],
-  rules: {
-    'github/array-foreach': 'error',
-    'import/default': 'error',
-    'import/export': 'error',
-    'import/first': 'error',
-    'import/named': 'error',
-    'import/namespace': 'error',
-    'import/no-absolute-path': 'error',
-    'import/no-anonymous-default-export': [
-      'error',
-      {
-        allowAnonymousClass: false,
-        allowAnonymousFunction: false,
-        allowArray: true,
-        allowArrowFunction: false,
-        allowLiteral: true,
-        allowObject: true
-      }
-    ],
-    'import/no-deprecated': 'error',
-    'import/no-duplicates': 'error',
-    'import/no-mutable-exports': 'error',
-    'import/no-named-as-default-member': 'error',
-    'import/no-named-as-default': 'error',
-    'import/no-namespace': 'error',
-    'no-var': 'error',
-    'prefer-const': 'error',
-    'prefer-rest-params': 'error',
-    'prefer-spread': 'error',
-    'prefer-template': 'error'
-  },
-  settings: {
-    'import/resolver': {
-      node: {
-        extensions: ['.js', '.ts']
-      }
-    }
-  },
-  extends: [require.resolve('./recommended')]
-}
diff --git a/lib/configs/recommended.js b/lib/configs/recommended.js
index fd0d0bf8..43bc3fbc 100644
--- a/lib/configs/recommended.js
+++ b/lib/configs/recommended.js
@@ -1,8 +1,14 @@
 module.exports = {
-  plugins: ['github', 'prettier', 'eslint-comments'],
+  parserOptions: {
+    ecmaFeatures: {
+      ecmaVersion: 6
+    },
+    sourceType: 'module'
+  },
   env: {
-    commonjs: true
+    es6: true
   },
+  plugins: ['github', 'prettier', 'eslint-comments', 'import'],
   rules: {
     'constructor-super': 'error',
     'eslint-comments/disable-enable-pair': 'off',
@@ -13,7 +19,31 @@ module.exports = {
     'eslint-comments/no-unused-enable': 'error',
     'eslint-comments/no-use': ['error', {allow: ['eslint', 'eslint-disable-next-line', 'eslint-env', 'globals']}],
     'func-style': ['error', 'declaration', {allowArrowFunctions: true}],
+    'github/array-foreach': 'error',
     'github/no-implicit-buggy-globals': 'error',
+    'import/default': 'error',
+    'import/export': 'error',
+    'import/first': 'error',
+    'import/named': 'error',
+    'import/namespace': 'error',
+    'import/no-absolute-path': 'error',
+    'import/no-anonymous-default-export': [
+      'error',
+      {
+        allowAnonymousClass: false,
+        allowAnonymousFunction: false,
+        allowArray: true,
+        allowArrowFunction: false,
+        allowLiteral: true,
+        allowObject: true
+      }
+    ],
+    'import/no-deprecated': 'error',
+    'import/no-duplicates': 'error',
+    'import/no-mutable-exports': 'error',
+    'import/no-named-as-default': 'error',
+    'import/no-named-as-default-member': 'error',
+    'import/no-namespace': 'error',
     'no-case-declarations': 'error',
     'no-class-assign': 'error',
     'no-compare-neg-zero': 'error',
@@ -61,13 +91,25 @@ module.exports = {
     'no-unused-vars': 'error',
     'no-useless-concat': 'error',
     'no-useless-escape': 'error',
+    'no-var': 'error',
     'object-shorthand': ['error', 'always', {avoidQuotes: true}],
+    'prefer-const': 'error',
     'prefer-promise-reject-errors': 'error',
+    'prefer-rest-params': 'error',
+    'prefer-spread': 'error',
+    'prefer-template': 'error',
     'prettier/prettier': 'error',
     'require-yield': 'error',
     'use-isnan': 'error',
     'valid-typeof': 'error',
     camelcase: ['error', {properties: 'always'}],
     eqeqeq: ['error', 'smart']
+  },
+  settings: {
+    'import/resolver': {
+      node: {
+        extensions: ['.js', '.ts']
+      }
+    }
   }
 }
diff --git a/lib/index.js b/lib/index.js
index f1c30106..e0a4c486 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -17,7 +17,6 @@ module.exports = {
   configs: {
     app: require('./configs/app'),
     browser: require('./configs/browser'),
-    es6: require('./configs/es6'),
     recommended: require('./configs/recommended'),
     typescript: require('./configs/typescript')
   }
diff --git a/lib/rules/js-class-name.js b/lib/rules/js-class-name.js
index 14f27a17..e2f2a6c5 100644
--- a/lib/rules/js-class-name.js
+++ b/lib/rules/js-class-name.js
@@ -5,17 +5,17 @@ module.exports = {
   },
 
   create(context) {
-    var allJsClassNameRegexp = /\bjs-[_a-zA-Z0-9-]*/g
-    var validJsClassNameRegexp = /^js(-[a-z0-9]+)+$/g
-    var endWithJsClassNameRegexp = /\bjs-[_a-zA-Z0-9-]*$/g
+    const allJsClassNameRegexp = /\bjs-[_a-zA-Z0-9-]*/g
+    const validJsClassNameRegexp = /^js(-[a-z0-9]+)+$/g
+    const endWithJsClassNameRegexp = /\bjs-[_a-zA-Z0-9-]*$/g
 
     function checkStringFormat(node, str) {
-      var matches = str.match(allJsClassNameRegexp) || []
-      matches.forEach(function(match) {
+      const matches = str.match(allJsClassNameRegexp) || []
+      for (const match of matches) {
         if (!match.match(validJsClassNameRegexp)) {
           context.report(node, 'js- class names should be lowercase and only contain dashes.')
         }
-      })
+      }
     }
 
     function checkStringEndsWithJSClassName(node, str) {
@@ -40,13 +40,13 @@ module.exports = {
         }
       },
       TemplateLiteral(node) {
-        node.quasis.forEach(function(quasi) {
+        for (const quasi of node.quasis) {
           checkStringFormat(quasi, quasi.value.raw)
 
           if (quasi.tail === false) {
             checkStringEndsWithJSClassName(quasi, quasi.value.raw)
           }
-        })
+        }
       }
     }
   }
diff --git a/lib/rules/no-implicit-buggy-globals.js b/lib/rules/no-implicit-buggy-globals.js
index ef48b025..66348812 100644
--- a/lib/rules/no-implicit-buggy-globals.js
+++ b/lib/rules/no-implicit-buggy-globals.js
@@ -7,14 +7,14 @@ module.exports = {
   create(context) {
     return {
       Program() {
-        var scope = context.getScope()
+        const scope = context.getScope()
 
-        scope.variables.forEach(function(variable) {
+        for (const variable of scope.variables) {
           if (variable.writeable) {
             return
           }
 
-          variable.defs.forEach(function(def) {
+          for (const def of variable.defs) {
             if (
               def.type === 'FunctionName' ||
               def.type === 'ClassName' ||
@@ -23,8 +23,8 @@ module.exports = {
             ) {
               context.report(def.node, 'Implicit global variable, assign as global property instead.')
             }
-          })
-        })
+          }
+        }
       }
     }
   }
diff --git a/tests/array-foreach.js b/tests/array-foreach.js
index 72609a80..3bfcd924 100644
--- a/tests/array-foreach.js
+++ b/tests/array-foreach.js
@@ -1,7 +1,7 @@
-var rule = require('../lib/rules/array-foreach')
-var RuleTester = require('eslint').RuleTester
+const rule = require('../lib/rules/array-foreach')
+const RuleTester = require('eslint').RuleTester
 
-var ruleTester = new RuleTester()
+const ruleTester = new RuleTester()
 
 ruleTester.run('array-foreach', rule, {
   valid: [
diff --git a/tests/async-currenttarget.js b/tests/async-currenttarget.js
index f4bc16c0..59e8a5c6 100644
--- a/tests/async-currenttarget.js
+++ b/tests/async-currenttarget.js
@@ -1,7 +1,7 @@
-var rule = require('../lib/rules/async-currenttarget')
-var RuleTester = require('eslint').RuleTester
+const rule = require('../lib/rules/async-currenttarget')
+const RuleTester = require('eslint').RuleTester
 
-var ruleTester = new RuleTester()
+const ruleTester = new RuleTester()
 
 ruleTester.run('async-currenttarget', rule, {
   valid: [
diff --git a/tests/async-preventdefault.js b/tests/async-preventdefault.js
index 06bc1099..35861f0c 100644
--- a/tests/async-preventdefault.js
+++ b/tests/async-preventdefault.js
@@ -1,7 +1,7 @@
-var rule = require('../lib/rules/async-preventdefault')
-var RuleTester = require('eslint').RuleTester
+const rule = require('../lib/rules/async-preventdefault')
+const RuleTester = require('eslint').RuleTester
 
-var ruleTester = new RuleTester()
+const ruleTester = new RuleTester()
 
 ruleTester.run('async-preventdefault', rule, {
   valid: [
diff --git a/tests/authenticity-token.js b/tests/authenticity-token.js
index bd567ae1..3c955871 100644
--- a/tests/authenticity-token.js
+++ b/tests/authenticity-token.js
@@ -1,7 +1,7 @@
-var rule = require('../lib/rules/authenticity-token')
-var RuleTester = require('eslint').RuleTester
+const rule = require('../lib/rules/authenticity-token')
+const RuleTester = require('eslint').RuleTester
 
-var ruleTester = new RuleTester()
+const ruleTester = new RuleTester()
 
 ruleTester.run('authenticity-token', rule, {
   valid: [],
diff --git a/tests/get-attribute.js b/tests/get-attribute.js
index f8ffa009..f756ff14 100644
--- a/tests/get-attribute.js
+++ b/tests/get-attribute.js
@@ -1,7 +1,7 @@
-var rule = require('../lib/rules/get-attribute')
-var RuleTester = require('eslint').RuleTester
+const rule = require('../lib/rules/get-attribute')
+const RuleTester = require('eslint').RuleTester
 
-var ruleTester = new RuleTester()
+const ruleTester = new RuleTester()
 
 ruleTester.run('get-attribute', rule, {
   valid: [
diff --git a/tests/js-class-name.js b/tests/js-class-name.js
index 392ed284..1aa829f9 100644
--- a/tests/js-class-name.js
+++ b/tests/js-class-name.js
@@ -1,7 +1,7 @@
-var rule = require('../lib/rules/js-class-name')
-var RuleTester = require('eslint').RuleTester
+const rule = require('../lib/rules/js-class-name')
+const RuleTester = require('eslint').RuleTester
 
-var ruleTester = new RuleTester()
+const ruleTester = new RuleTester()
 
 ruleTester.run('js-class-name', rule, {
   valid: [
diff --git a/tests/no-blur.js b/tests/no-blur.js
index f5fffd30..086cf2d6 100644
--- a/tests/no-blur.js
+++ b/tests/no-blur.js
@@ -1,7 +1,7 @@
-var rule = require('../lib/rules/no-blur')
-var RuleTester = require('eslint').RuleTester
+const rule = require('../lib/rules/no-blur')
+const RuleTester = require('eslint').RuleTester
 
-var ruleTester = new RuleTester()
+const ruleTester = new RuleTester()
 
 ruleTester.run('no-blur', rule, {
   valid: [{code: 'target.focus()'}],
diff --git a/tests/no-d-none.js b/tests/no-d-none.js
index 20aa1f13..ecee4ba7 100644
--- a/tests/no-d-none.js
+++ b/tests/no-d-none.js
@@ -1,7 +1,7 @@
-var rule = require('../lib/rules/no-d-none')
-var RuleTester = require('eslint').RuleTester
+const rule = require('../lib/rules/no-d-none')
+const RuleTester = require('eslint').RuleTester
 
-var ruleTester = new RuleTester()
+const ruleTester = new RuleTester()
 
 ruleTester.run('no-d-none', rule, {
   valid: [
diff --git a/tests/no-dataset.js b/tests/no-dataset.js
index 512fe9a1..d1116dea 100644
--- a/tests/no-dataset.js
+++ b/tests/no-dataset.js
@@ -1,7 +1,7 @@
-var rule = require('../lib/rules/no-dataset')
-var RuleTester = require('eslint').RuleTester
+const rule = require('../lib/rules/no-dataset')
+const RuleTester = require('eslint').RuleTester
 
-var ruleTester = new RuleTester()
+const ruleTester = new RuleTester()
 
 ruleTester.run('no-dataset', rule, {
   valid: [
diff --git a/tests/no-implicit-buggy-globals.js b/tests/no-implicit-buggy-globals.js
index 5d0c6476..a21e739d 100644
--- a/tests/no-implicit-buggy-globals.js
+++ b/tests/no-implicit-buggy-globals.js
@@ -1,7 +1,7 @@
-var rule = require('../lib/rules/no-implicit-buggy-globals')
-var RuleTester = require('eslint').RuleTester
+const rule = require('../lib/rules/no-implicit-buggy-globals')
+const RuleTester = require('eslint').RuleTester
 
-var ruleTester = new RuleTester()
+const ruleTester = new RuleTester()
 
 ruleTester.run('no-implicit-buggy-globals', rule, {
   valid: [
diff --git a/tests/no-innerText.js b/tests/no-innerText.js
index 4dc7ef39..89832df4 100644
--- a/tests/no-innerText.js
+++ b/tests/no-innerText.js
@@ -1,7 +1,7 @@
-var rule = require('../lib/rules/no-innerText')
-var RuleTester = require('eslint').RuleTester
+const rule = require('../lib/rules/no-innerText')
+const RuleTester = require('eslint').RuleTester
 
-var ruleTester = new RuleTester()
+const ruleTester = new RuleTester()
 
 ruleTester.run('no-innerText', rule, {
   valid: [
diff --git a/tests/no-then.js b/tests/no-then.js
index fb7fce0d..7fe6ca37 100644
--- a/tests/no-then.js
+++ b/tests/no-then.js
@@ -1,7 +1,7 @@
-var rule = require('../lib/rules/no-then')
-var RuleTester = require('eslint').RuleTester
+const rule = require('../lib/rules/no-then')
+const RuleTester = require('eslint').RuleTester
 
-var ruleTester = new RuleTester()
+const ruleTester = new RuleTester()
 
 ruleTester.run('no-then', rule, {
   valid: [
diff --git a/tests/unescaped-html-literal.js b/tests/unescaped-html-literal.js
index 29b00356..2bfaca76 100644
--- a/tests/unescaped-html-literal.js
+++ b/tests/unescaped-html-literal.js
@@ -1,7 +1,7 @@
-var rule = require('../lib/rules/unescaped-html-literal')
-var RuleTester = require('eslint').RuleTester
+const rule = require('../lib/rules/unescaped-html-literal')
+const RuleTester = require('eslint').RuleTester
 
-var ruleTester = new RuleTester()
+const ruleTester = new RuleTester()
 
 ruleTester.run('unescaped-html-literal', rule, {
   valid: [