diff --git a/.editorconfig b/.editorconfig
index 98a761d..1c6314a 100644
--- a/.editorconfig
+++ b/.editorconfig
@@ -7,6 +7,6 @@ charset = utf-8
 trim_trailing_whitespace = true
 insert_final_newline = true
 
-[{package.json,*.yml}]
+[*.yml]
 indent_style = space
 indent_size = 2
diff --git a/.gitattributes b/.gitattributes
index 176a458..6313b56 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -1 +1 @@
-* text=auto
+* text=auto eol=lf
diff --git a/.gitignore b/.gitignore
index 3c3629e..239ecff 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
 node_modules
+yarn.lock
diff --git a/.npmrc b/.npmrc
new file mode 100644
index 0000000..43c97e7
--- /dev/null
+++ b/.npmrc
@@ -0,0 +1 @@
+package-lock=false
diff --git a/.travis.yml b/.travis.yml
index a78e23d..f3fa8cd 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,7 +1,4 @@
-sudo: false
 language: node_js
 node_js:
-  - '5'
-  - '4'
-  - '0.12'
-  - '0.10'
+  - '10'
+  - '8'
diff --git a/index.d.ts b/index.d.ts
new file mode 100644
index 0000000..150e727
--- /dev/null
+++ b/index.d.ts
@@ -0,0 +1,25 @@
+declare const detectNewline: {
+	/**
+	Detect the dominant newline character of a string.
+
+	@returns Detected newline or `null` when no newline character is found.
+
+	@example
+	```
+	import detectNewline = require('detect-newline');
+
+	detectNewline('foo\nbar\nbaz\r\n');
+	//=> '\n'
+	```
+	*/
+	(string: string): '\r\n' | '\n' | null;
+
+	/**
+	Detect the dominant newline character of a string.
+
+	@returns Returns detected newline or `\n` when no newline character is found.
+	*/
+	graceful(string: string): '\r\n' | '\n';
+};
+
+export = detectNewline;
diff --git a/index.js b/index.js
index 940329e..e24045a 100644
--- a/index.js
+++ b/index.js
@@ -1,24 +1,20 @@
 'use strict';
-module.exports = function (str) {
-	if (typeof str !== 'string') {
+const detectNewline = string => {
+	if (typeof string !== 'string') {
 		throw new TypeError('Expected a string');
 	}
 
-	var newlines = (str.match(/(?:\r?\n)/g) || []);
+	const newlines = string.match(/(?:\r?\n)/g) || [];
 
 	if (newlines.length === 0) {
 		return null;
 	}
 
-	var crlf = newlines.filter(function (el) {
-		return el === '\r\n';
-	}).length;
-
-	var lf = newlines.length - crlf;
+	const crlf = newlines.filter(el => el === '\r\n').length;
+	const lf = newlines.length - crlf;
 
 	return crlf > lf ? '\r\n' : '\n';
 };
 
-module.exports.graceful = function (str) {
-	return module.exports(str) || '\n';
-};
+module.exports = detectNewline;
+module.exports.graceful = string => detectNewline(string) || '\n';
diff --git a/index.test-d.ts b/index.test-d.ts
new file mode 100644
index 0000000..2cc3210
--- /dev/null
+++ b/index.test-d.ts
@@ -0,0 +1,5 @@
+import {expectType} from 'tsd';
+import detectNewline = require('.');
+
+expectType<'\r\n' | '\n' | null>(detectNewline('foo\nbar\nbaz\r\n'));
+expectType<'\r\n' | '\n'>(detectNewline.graceful('foo\nbar\nbaz\r\n'));
diff --git a/license b/license
index 654d0bf..e7af2f7 100644
--- a/license
+++ b/license
@@ -1,21 +1,9 @@
-The MIT License (MIT)
+MIT License
 
 Copyright (c) Sindre Sorhus <sindresorhus@gmail.com> (sindresorhus.com)
 
-Permission is hereby granted, free of charge, to any person obtaining a copy
-of this software and associated documentation files (the "Software"), to deal
-in the Software without restriction, including without limitation the rights
-to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-copies of the Software, and to permit persons to whom the Software is
-furnished to do so, subject to the following conditions:
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
 
-The above copyright notice and this permission notice shall be included in
-all copies or substantial portions of the Software.
+The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
 
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-THE SOFTWARE.
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
diff --git a/package.json b/package.json
index d5b3d67..14da6e5 100644
--- a/package.json
+++ b/package.json
@@ -1,37 +1,39 @@
 {
-  "name": "detect-newline",
-  "version": "2.1.0",
-  "description": "Detect the dominant newline character of a string",
-  "license": "MIT",
-  "repository": "sindresorhus/detect-newline",
-  "author": {
-    "name": "Sindre Sorhus",
-    "email": "sindresorhus@gmail.com",
-    "url": "sindresorhus.com"
-  },
-  "engines": {
-    "node": ">=0.10.0"
-  },
-  "scripts": {
-    "test": "xo && ava"
-  },
-  "files": [
-    "index.js"
-  ],
-  "keywords": [
-    "newline",
-    "linebreak",
-    "line-break",
-    "line",
-    "lf",
-    "crlf",
-    "eol",
-    "linefeed",
-    "character",
-    "char"
-  ],
-  "devDependencies": {
-    "ava": "*",
-    "xo": "*"
-  }
+	"name": "detect-newline",
+	"version": "2.1.0",
+	"description": "Detect the dominant newline character of a string",
+	"license": "MIT",
+	"repository": "sindresorhus/detect-newline",
+	"author": {
+		"name": "Sindre Sorhus",
+		"email": "sindresorhus@gmail.com",
+		"url": "sindresorhus.com"
+	},
+	"engines": {
+		"node": ">=8"
+	},
+	"scripts": {
+		"test": "xo && ava && tsd"
+	},
+	"files": [
+		"index.js",
+		"index.d.ts"
+	],
+	"keywords": [
+		"newline",
+		"linebreak",
+		"line-break",
+		"line",
+		"lf",
+		"crlf",
+		"eol",
+		"linefeed",
+		"character",
+		"char"
+	],
+	"devDependencies": {
+		"ava": "^1.4.1",
+		"tsd": "^0.7.2",
+		"xo": "^0.24.0"
+	}
 }
diff --git a/readme.md b/readme.md
index ec5a479..c0d2274 100644
--- a/readme.md
+++ b/readme.md
@@ -6,7 +6,7 @@
 ## Install
 
 ```
-$ npm install --save detect-newline
+$ npm install detect-newline
 ```
 
 
@@ -22,11 +22,11 @@ detectNewline('foo\nbar\nbaz\r\n');
 
 ## API
 
-### detectNewline(input)
+### detectNewline(string)
 
 Returns detected newline or `null` when no newline character is found.
 
-### detectNewline.graceful(input)
+### detectNewline.graceful(string)
 
 Returns detected newline or `\n` when no newline character is found.
 
diff --git a/test.js b/test.js
index 6e53743..a09e013 100644
--- a/test.js
+++ b/test.js
@@ -1,11 +1,11 @@
 import test from 'ava';
-import m from './';
+import detectNewline from '.';
 
-test(t => {
-	t.is(m('foo\r\nbar\r\nbaz\n\n\n'), '\n');
-	t.is(m('foo\r\nbar\r\nbaz\n'), '\r\n');
-	t.is(m('foo\nbar\nbaz\r\n'), '\n');
-	t.is(m('foo\nbar\r\n'), '\n');
-	t.is(m('foo'), null);
-	t.is(m.graceful('foo'), '\n');
+test('main', t => {
+	t.is(detectNewline('foo\r\nbar\r\nbaz\n\n\n'), '\n');
+	t.is(detectNewline('foo\r\nbar\r\nbaz\n'), '\r\n');
+	t.is(detectNewline('foo\nbar\nbaz\r\n'), '\n');
+	t.is(detectNewline('foo\nbar\r\n'), '\n');
+	t.is(detectNewline('foo'), null);
+	t.is(detectNewline.graceful('foo'), '\n');
 });