diff --git a/.travis.yml b/.travis.yml
index 8e18725..ff4ce38 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -3,9 +3,9 @@ sudo: false
 language: node_js
 
 node_js:
-  - 6
-  - 8
   - 10
+  - 12
+  - 14
 
 after_success: npm run coverage
 
diff --git a/README.md b/README.md
index c832132..72ed0dc 100644
--- a/README.md
+++ b/README.md
@@ -15,14 +15,18 @@
 ## Usage
 
 ```js
-var concat = require('level-concat-iterator')
-var level = require('level')
-
-level('DB', function (err, db) {
-  db.put('foo', 'bar', function (err) {
-    concat(db.iterator(), function (err, data) {
-      console.log(data)
-    })
+const concat = require('level-concat-iterator')
+const level = require('level')
+
+const db = level('./db')
+
+db.put('foo', 'bar', function (err) {
+  if (err) throw err
+
+  concat(db.iterator(), function (err, data) {
+    if (err) throw err
+
+    console.log(data)
   })
 })
 ```
diff --git a/example.js b/example.js
index 624bc32..51f38be 100644
--- a/example.js
+++ b/example.js
@@ -1,13 +1,14 @@
-var level = require('level')
-var concat = require('.')
+const level = require('level')
+const concat = require('.')
 
-level('DB', function (err, db) {
+const db = level('./db')
+
+db.put('foo', 'bar', function (err) {
   if (err) throw err
-  db.put('foo', 'bar', function (err) {
+
+  concat(db.iterator(), function (err, data) {
     if (err) throw err
-    concat(db.iterator(), function (err, data) {
-      if (err) throw err
-      console.log(data)
-    })
+
+    console.log(data)
   })
 })
diff --git a/index.js b/index.js
index 1a267e0..4ed5c03 100644
--- a/index.js
+++ b/index.js
@@ -1,13 +1,15 @@
+'use strict'
+
 module.exports = function (iterator, cb) {
-  var data = []
-  var next = function () {
+  const data = []
+  const next = function () {
     iterator.next(function (err, key, value) {
       if (err || (key === undefined && value === undefined)) {
         return iterator.end(function (err2) {
           cb(err || err2, data)
         })
       }
-      data.push({ key: key, value: value })
+      data.push({ key, value })
       next()
     })
   }
diff --git a/package.json b/package.json
index aad37aa..d323b1b 100644
--- a/package.json
+++ b/package.json
@@ -18,7 +18,7 @@
     "hallmark": "^3.1.0",
     "level-community": "^3.0.0",
     "nyc": "^14.0.0",
-    "standard": "^14.0.0",
+    "standard": "^16.0.3",
     "tape": "^5.0.1"
   },
   "hallmark": {
@@ -36,6 +36,6 @@
     "array"
   ],
   "engines": {
-    "node": ">=6"
+    "node": ">=10"
   }
 }
diff --git a/test.js b/test.js
index bf09227..905c346 100644
--- a/test.js
+++ b/test.js
@@ -1,15 +1,17 @@
-var test = require('tape')
-var collect = require('.')
+'use strict'
+
+const test = require('tape')
+const collect = require('.')
 
 test('calls back with error if iterator.next errors', function (t) {
   t.plan(3)
 
-  var iterator = {
-    next: function (cb) {
+  const iterator = {
+    next (cb) {
       t.pass('iterator.next called')
       process.nextTick(cb, new Error('iterator.next'))
     },
-    end: function (cb) {
+    end (cb) {
       t.pass('iterator.end called')
       process.nextTick(cb)
     }
@@ -23,14 +25,14 @@ test('calls back with error if iterator.next errors', function (t) {
 test('happy path calls back with an array', function (t) {
   t.plan(6)
 
-  var i = 0
-  var data = [
+  let i = 0
+  const data = [
     { key: 'key1', value: 'value1' },
     { key: 'key2', value: 'value2' }
   ]
 
-  var iterator = {
-    next: function (cb) {
+  const iterator = {
+    next (cb) {
       t.pass('iterator.next called')
       if (i < data.length) {
         process.nextTick(cb, null, data[i].key, data[i].value)
@@ -39,7 +41,7 @@ test('happy path calls back with an array', function (t) {
         process.nextTick(cb)
       }
     },
-    end: function (cb) {
+    end (cb) {
       t.pass('iterator.end called')
       process.nextTick(cb)
     }
@@ -54,14 +56,14 @@ test('happy path calls back with an array', function (t) {
 test('calls back with error and data if iterator.end errors', function (t) {
   t.plan(6)
 
-  var i = 0
-  var data = [
+  let i = 0
+  const data = [
     { key: 'key1', value: 'value1' },
     { key: 'key2', value: 'value2' }
   ]
 
-  var iterator = {
-    next: function (cb) {
+  const iterator = {
+    next (cb) {
       t.pass('iterator.next called')
       if (i < data.length) {
         process.nextTick(cb, null, data[i].key, data[i].value)
@@ -70,7 +72,7 @@ test('calls back with error and data if iterator.end errors', function (t) {
         process.nextTick(cb)
       }
     },
-    end: function (cb) {
+    end (cb) {
       t.pass('iterator.end called')
       process.nextTick(cb, new Error('iterator.end'))
     }
@@ -85,14 +87,14 @@ test('calls back with error and data if iterator.end errors', function (t) {
 test('calls back with error and partial data if iterator.end errors', function (t) {
   t.plan(5)
 
-  var i = 0
-  var data = [
+  let i = 0
+  const data = [
     { key: 'key1', value: 'value1' },
     { key: 'key2', value: 'value2' }
   ]
 
-  var iterator = {
-    next: function (cb) {
+  const iterator = {
+    next (cb) {
       t.pass('iterator.next called')
       if (i === 0) {
         process.nextTick(cb, null, data[i].key, data[i].value)
@@ -101,7 +103,7 @@ test('calls back with error and partial data if iterator.end errors', function (
         process.nextTick(cb)
       }
     },
-    end: function (cb) {
+    end (cb) {
       t.pass('iterator.end called')
       process.nextTick(cb, new Error('foo'))
     }