diff --git a/.flowconfig b/.flowconfig
deleted file mode 100644
index e69de29..0000000
diff --git a/.travis.yml b/.travis.yml
index d015b93..5e3bcf3 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -2,7 +2,5 @@ language: node_js
 node_js:
   - '10'
   - '8'
-before_script:
-  - './node_modules/.bin/flow check'
 after_success:
   - './node_modules/.bin/nyc report --reporter=text-lcov | ./node_modules/.bin/coveralls'
diff --git a/global.d.ts b/global.d.ts
new file mode 100644
index 0000000..1e7fd7c
--- /dev/null
+++ b/global.d.ts
@@ -0,0 +1 @@
+declare module '*';
\ No newline at end of file
diff --git a/lib/index.js b/lib/index.ts
similarity index 74%
rename from lib/index.js
rename to lib/index.ts
index 769a277..3c37bd2 100644
--- a/lib/index.js
+++ b/lib/index.ts
@@ -1,9 +1,7 @@
-// @flow
-/* eslint-disable no-use-before-define */
 import path from 'path';
 import EventEmitter from 'events';
 import {Readable} from 'stream';
-import url from 'url';
+import {parse as parseUrl} from 'url';
 import arrayUniq from 'array-uniq';
 import arrayDiffer from 'array-differ';
 import easydate from 'easydate';
@@ -22,63 +20,65 @@ import template from 'lodash.template';
 import plur from 'plur';
 import unusedFilename from 'unused-filename';
 
-type PageresStream = Readable & {filename: string};
+interface PageresStream extends Readable {
+	filename: string;
+}
 
-type Options = {
+interface Options {
 	delay?: number;
 	timeout?: number;
 	crop?: boolean;
 	incrementalName?: boolean;
 	css?: string;
-	cookies?: Array<string> | {[key: string]: string};
+	cookies?: string[] | {[key: string]: string};
 	filename?: string;
 	selector?: string;
-	hide?: Array<string>;
+	hide?: string[];
 	username?: string;
 	password?: string;
 	scale?: number;
 	format?: string;
 	userAgent?: string;
 	headers?: {[key: string]: string};
-};
+}
 
-type Src = {
+interface Src {
 	url: string;
-	sizes: Array<string>;
-	options: Options;
-};
+	sizes: string[];
+	options?: Options;
+}
 
-type Viewport = {
-	url: string;
-	sizes: Array<string>;
-	keywords: Array<string>;
-};
+type DestValue = string;
 
-type SrcFn<DestValue> =
-	& ((_: void, _: void, _: void) => Array<Src>)
-	& ((url: string, sizes: Array<string>, options: Options) => Pageres<DestValue>);
+interface Viewport {
+	url: string;
+	sizes: string[];
+	keywords: string[];
+}
 
-type DestFn<DestValue> =
-	& ((_: void) => DestValue)
-	& ((dir: DestValue) => Pageres<DestValue>);
+interface Stats {
+	urls?: number;
+	sizes?: number;
+	screenshots?: number;
+}
 
 const getResMem = mem(getRes);
 const viewportListMem = mem(viewportList);
 
-let listener;
+let listener : NodeJS.Process;
 
-export default class Pageres<DestValue: string> extends EventEmitter {
+export default class Pageres extends EventEmitter {
 	options: Options;
 
-	stats: Object;
+	stats: Stats;
 
-	items: Array<PageresStream>;
+	items: PageresStream[];
 
-	sizes: Array<string>;
+	sizes: string[];
 
-	urls: Array<string>;
+	urls: string[];
 
-	_src: Array<Src>;
+	_src: Src[];
 
 	_dest: DestValue;
 
@@ -95,22 +95,28 @@ export default class Pageres<DestValue: string> extends EventEmitter {
 		this.sizes = [];
 		this.urls = [];
 		this._src = [];
+		this._dest = '';
 	}
 
-	src: SrcFn<DestValue>;
-
-	src(url: string, sizes: Array<string>, options: Options) {
+	src() : Src[];
+	src(url: string, sizes: string[], options?: Options) : this;
+	src(url?: string, sizes?: string[], options?: Options) : this | Src[] {
 		if (url === undefined) {
 			return this._src;
 		}
 
+		if (sizes === undefined) {
+			throw new TypeError('Sizes required');
+		}
+
 		this._src.push({url, sizes, options});
 		return this;
 	}
 
-	dest: DestFn<DestValue>;
+	dest() : DestValue;
+	dest(dir: DestValue) : this;
 
-	dest(dir: DestValue) {
+	dest(dir?: DestValue) : this | DestValue {
 		if (dir === undefined) {
 			return this._dest;
 		}
@@ -120,15 +126,15 @@ export default class Pageres<DestValue: string> extends EventEmitter {
 	}
 
 	async run(): Promise<PageresStream[]> {
-		await Promise.all(this.src().map(src => { // eslint-disable-line array-callback-return
-			const options = {...this.options, ...src.options};
-			const sizes = arrayUniq(src.sizes.filter(/./.test, /^\d{2,4}x\d{2,4}$/i));
-			const keywords = arrayDiffer(src.sizes, sizes);
-
+		await Promise.all(this.src().map((src: Src) : Promise<void> | void => {
 			if (!src.url) {
 				throw new Error('URL required');
 			}
 
+			const options = {...this.options, ...src.options};
+			const sizes = arrayUniq(src.sizes.filter(/./.test, /^\d{2,4}x\d{2,4}$/i));
+			const keywords = arrayDiffer(src.sizes, sizes);
+
 			this.urls.push(src.url);
 
 			if (sizes.length === 0 && keywords.indexOf('w3counter') !== -1) {
@@ -176,8 +182,8 @@ export default class Pageres<DestValue: string> extends EventEmitter {
 		}
 	}
 
-	save(streams: Array<PageresStream>) {
-		const files = [];
+	async save(streams: PageresStream[]) {
+		const files: any[] = [];
 
 		const end = () => del(files, {force: true});
 
@@ -188,8 +194,7 @@ export default class Pageres<DestValue: string> extends EventEmitter {
 			});
 		}
 
-		return Promise.all(streams.map(stream =>
-			// eslint-disable-next-line no-async-promise-executor
+		return Promise.all(streams.map(async stream =>
 			new Promise(async (resolve, reject) => {
 				await makeDir(this.dest());
 
@@ -206,7 +211,7 @@ export default class Pageres<DestValue: string> extends EventEmitter {
 				});
 
 				write.on('finish', resolve);
-				write.on('error', async err => {
+				write.on('error', async (err: any) => {
 					await end();
 					reject(err);
 				});
@@ -218,16 +223,10 @@ export default class Pageres<DestValue: string> extends EventEmitter {
 	create(uri: string, size: string, options: Options) {
 		const sizes = size.split('x');
 		const stream = screenshotStream(protocolify(uri), size, options);
+		const filename = template(`${options.filename}.${options.format}`);
+		const basename = path.isAbsolute(uri) ? path.basename(uri) : uri;
 
-		// Coercing to string here to please Flow
-		// TODO: Should fix the Flow type so this isn't necessary
-		const filename = template(`${String(options.filename)}.${String(options.format)}`);
-
-		let hash = url.parse(uri).hash || '';
-
-		if (path.isAbsolute(uri)) {
-			uri = path.basename(uri);
-		}
+		let hash = parseUrl(uri).hash || '';
 
 		// Strip empty hash fragments: `#` `#/` `#!/`
 		if (/^#!?\/?$/.test(hash)) {
@@ -241,7 +240,7 @@ export default class Pageres<DestValue: string> extends EventEmitter {
 			size,
 			width: sizes[0],
 			height: sizes[1],
-			url: filenamifyUrl(uri) + filenamify(hash)
+			url: `${filenamifyUrl(basename)}${filenamify(hash)}`
 		});
 
 		if (options.incrementalName) {
@@ -252,8 +251,7 @@ export default class Pageres<DestValue: string> extends EventEmitter {
 	}
 
 	successMessage() {
-		const {stats} = this;
-		const {screenshots, sizes, urls} = stats;
+		const {screenshots, sizes, urls} = this.stats;
 		const words = {
 			screenshots: plur('screenshot', screenshots),
 			sizes: plur('size', sizes),
diff --git a/package.json b/package.json
index 264d226..c5a2875 100644
--- a/package.json
+++ b/package.json
@@ -26,9 +26,10 @@
 		"node": ">=8"
 	},
 	"scripts": {
-		"test": "xo && npm run prepublish && nyc ava",
-		"flow": "flow || true",
-		"prepublish": "babel lib --out-dir=dist"
+		"test": "npm run lint && npm run build && nyc ava",
+		"lint": "tslint --format stylish --project . && xo",
+		"build": "del dist && tsc",
+		"prepublish": "npm run build"
 	},
 	"files": [
 		"dist"
@@ -84,18 +85,11 @@
 		"viewport-list": "^5.0.1"
 	},
 	"devDependencies": {
+		"@types/node": "^10.12.0",
 		"ava": "*",
-		"babel-cli": "^6.7.5",
-		"babel-eslint": "^8.0.1",
-		"babel-plugin-add-module-exports": "^0.2.1",
-		"babel-plugin-transform-async-to-generator": "^6.7.4",
-		"babel-plugin-transform-flow-strip-types": "^6.14.0",
-		"babel-plugin-transform-object-rest-spread": "^6.26.0",
-		"babel-plugin-transform-runtime": "^6.7.5",
-		"babel-preset-es2015-node4": "^2.1.0",
 		"cookie": "^0.3.1",
 		"coveralls": "^3.0.0",
-		"flow-bin": "^0.57.3",
+		"del-cli": "^1.1.0",
 		"get-port": "^3.0.0",
 		"get-stream": "^3.0.0",
 		"image-size": "^0.6.0",
@@ -104,25 +98,9 @@
 		"pify": "^3.0.0",
 		"png-js": "^0.1.1",
 		"sinon": "^4.0.1",
+		"tslint": "^5.11.0",
+		"tslint-xo": "^0.9.0",
+		"typescript": "^3.1.3",
 		"xo": "*"
-	},
-	"babel": {
-		"plugins": [
-			"transform-async-to-generator",
-			"transform-object-rest-spread",
-			"transform-runtime",
-			"transform-flow-strip-types",
-			"add-module-exports"
-		],
-		"presets": [
-			"es2015-node4"
-		],
-		"sourceMaps": "inline"
-	},
-	"xo": {
-		"parser": "babel-eslint",
-		"rules": {
-			"generator-star-spacing": "off"
-		}
 	}
 }
diff --git a/test/test.js b/test/test.js
index bf526bf..de74a48 100644
--- a/test/test.js
+++ b/test/test.js
@@ -202,11 +202,11 @@ test('when a file exists, append an incrementer', async t => {
 	const folderPath = process.cwd();
 	try {
 		await new Pageres({delay: 2}).src('yeoman.io', ['1024x768', '480x320'], {incrementalName: true, filename: '<%= url %>'}).dest(folderPath).run();
-		t.true(fs.existsSync(path.join(folderPath, `yeoman.io.png`)));
+		t.true(fs.existsSync(path.join(folderPath, 'yeoman.io.png')));
 		await new Pageres({delay: 2}).src('yeoman.io', ['1024x768', '480x320'], {incrementalName: true, filename: '<%= url %>'}).dest(folderPath).run();
-		t.true(fs.existsSync(path.join(folderPath, `yeoman.io (1).png`)));
+		t.true(fs.existsSync(path.join(folderPath, 'yeoman.io (1).png')));
 	} finally {
-		await fsP.unlink(path.join(folderPath, `yeoman.io.png`));
-		await fsP.unlink(path.join(folderPath, `yeoman.io (1).png`));
+		await fsP.unlink(path.join(folderPath, 'yeoman.io.png'));
+		await fsP.unlink(path.join(folderPath, 'yeoman.io (1).png'));
 	}
 });
diff --git a/tsconfig.json b/tsconfig.json
new file mode 100644
index 0000000..d62bd39
--- /dev/null
+++ b/tsconfig.json
@@ -0,0 +1,30 @@
+{
+	"compilerOptions": {
+		"outDir": "dist",
+		"target": "es2016",
+		"lib": [
+			"es2016"
+		],
+		"module": "commonjs",
+		"moduleResolution": "node",
+		"esModuleInterop": true,
+		"allowSyntheticDefaultImports": true,
+		"sourceMap": true,
+		"declaration": true,
+		"pretty": true,
+		"newLine": "lf",
+		"stripInternal": true,
+		"strict": true,
+		"noImplicitReturns": true,
+		"noUnusedLocals": true,
+		"noUnusedParameters": true,
+		"noFallthroughCasesInSwitch": true,
+		"noEmitOnError": true,
+		"forceConsistentCasingInFileNames": true,
+		"skipLibCheck": true
+	},
+	"exclude": [
+		"node_modules",
+		"dist"
+	]
+}
diff --git a/tslint.json b/tslint.json
new file mode 100644
index 0000000..8731cf9
--- /dev/null
+++ b/tslint.json
@@ -0,0 +1,9 @@
+{
+	"extends": "tslint-xo",
+	"rules": {
+		"variable-name": [
+			true,
+			"allow-leading-underscore"
+		]
+	}
+}