diff --git a/.travis.yml b/.travis.yml
index 985b15c..a18175d 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -3,6 +3,6 @@ os:
   - windows
 language: node_js
 node_js:
+  - '14'
   - '12'
   - '10'
-  - '8'
diff --git a/fixture-no-compress.png b/fixture-no-compress.png
deleted file mode 100644
index 1310ac2..0000000
Binary files a/fixture-no-compress.png and /dev/null differ
diff --git a/index.d.ts b/index.d.ts
index 18d5599..89c3e55 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -55,7 +55,7 @@ export interface Options {
 /**
 Buffer or stream to optimize.
 */
-export type Plugin = (input: Buffer | NodeJS.ReadableStream) => Promise<Buffer>
+export type Plugin = (input: Buffer | NodeJS.ReadableStream) => Promise<Buffer>;
 
 /**
 Imagemin plugin for pngquant.
diff --git a/index.test-d.ts b/index.test-d.ts
index 3f62d83..28ea434 100644
--- a/index.test-d.ts
+++ b/index.test-d.ts
@@ -3,10 +3,12 @@ import * as path from 'path';
 import {expectType} from 'tsd';
 import imageminPngquant from '.';
 
-const buffer = await fs.readFileSync(path.join(__dirname, 'fixture.png'));
+const buffer = fs.readFileSync(path.join(__dirname, 'fixture.png'));
 
-expectType<Buffer>(await imageminPngquant()(buffer));
-expectType<Buffer>(await imageminPngquant({
-	speed: 10,
-	quality: [0.8, 1]
-})(buffer));
+(async () => {
+	expectType<Buffer>(await imageminPngquant()(buffer));
+	expectType<Buffer>(await imageminPngquant({
+		speed: 10,
+		quality: [0.8, 1]
+	})(buffer));
+})();
diff --git a/package.json b/package.json
index edd8d08..a9518ab 100644
--- a/package.json
+++ b/package.json
@@ -5,7 +5,7 @@
 	"license": "MIT",
 	"repository": "imagemin/imagemin-pngquant",
 	"engines": {
-		"node": ">=8"
+		"node": ">=10"
 	},
 	"scripts": {
 		"test": "xo && ava && tsd"
@@ -24,17 +24,17 @@
 		"pngquant"
 	],
 	"dependencies": {
-		"execa": "^1.0.0",
+		"execa": "^4.0.0",
 		"is-png": "^2.0.0",
 		"is-stream": "^2.0.0",
-		"ow": "^0.13.2",
-		"pngquant-bin": "^5.0.0"
+		"ow": "^0.17.0",
+		"pngquant-bin": "^6.0.0"
 	},
 	"devDependencies": {
 		"@types/node": "^12.0.3",
-		"ava": "^1.0.1",
+		"ava": "^3.8.0",
 		"get-stream": "^5.1.0",
-		"tsd": "^0.7.3",
-		"xo": "^0.24.0"
+		"tsd": "^0.11.0",
+		"xo": "^0.30.0"
 	}
 }
diff --git a/readme.md b/readme.md
index ef63bf5..e56cc55 100644
--- a/readme.md
+++ b/readme.md
@@ -17,7 +17,8 @@ const imagemin = require('imagemin');
 const imageminPngquant = require('imagemin-pngquant');
 
 (async () => {
-	await imagemin(['images/*.png'], 'build/images', {
+	await imagemin(['images/*.png'], {
+		destination: 'build/images',
 		plugins: [
 			imageminPngquant()
 		]
diff --git a/test.js b/test.js
index 9117929..7945384 100644
--- a/test.js
+++ b/test.js
@@ -1,19 +1,22 @@
-import fs from 'fs';
-import path from 'path';
-import test from 'ava';
-import getStream from 'get-stream';
-import isPng from 'is-png';
-import imageminPngquant from '.';
+const {promisify} = require('util');
+const fs = require('fs');
+const path = require('path');
+const test = require('ava');
+const getStream = require('get-stream');
+const isPng = require('is-png');
+const imageminPngquant = require('.');
+
+const readFile = promisify(fs.readFile);
 
 test('optimize a PNG', async t => {
-	const buffer = await fs.readFileSync(path.join(__dirname, 'fixture.png'));
+	const buffer = await readFile(path.join(__dirname, 'fixture.png'));
 	const data = await imageminPngquant()(buffer);
 	t.true(data.length < buffer.length);
 	t.true(isPng(data));
 });
 
 test('support pngquant options', async t => {
-	const buffer = await fs.readFileSync(path.join(__dirname, 'fixture.png'));
+	const buffer = await readFile(path.join(__dirname, 'fixture.png'));
 	const data = await imageminPngquant({
 		speed: 10,
 		quality: [0.8, 1]
@@ -23,7 +26,7 @@ test('support pngquant options', async t => {
 });
 
 test('support streams', async t => {
-	const buffer = await fs.readFileSync(path.join(__dirname, 'fixture.png'));
+	const buffer = await readFile(path.join(__dirname, 'fixture.png'));
 	const stream = fs.createReadStream(path.join(__dirname, 'fixture.png'));
 	const data = await getStream.buffer(imageminPngquant()(stream));
 	t.true(data.length < buffer.length);
@@ -31,14 +34,7 @@ test('support streams', async t => {
 });
 
 test('skip optimizing a non-PNG file', async t => {
-	const buffer = await fs.readFileSync(__filename);
+	const buffer = await readFile(__filename);
 	const data = await imageminPngquant()(buffer);
 	t.is(data.length, buffer.length);
 });
-
-test('skip optimizing a fully optimized PNG', async t => {
-	const buffer = await fs.readFileSync(path.join(__dirname, 'fixture-no-compress.png'));
-	const data = await imageminPngquant({quality: [0.8, 1]})(buffer);
-	t.is(data.length, buffer.length);
-	t.true(isPng(data));
-});