diff --git a/.github/FUNDING.yml b/.github/FUNDING.yml
new file mode 100644
index 0000000..a858fe0
--- /dev/null
+++ b/.github/FUNDING.yml
@@ -0,0 +1 @@
+github: lukeed
\ No newline at end of file
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 0000000..96fa516
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,20 @@
+name: CI
+
+on: [push, pull_request]
+
+jobs:
+  test:
+    name: Node.js v6
+    runs-on: ubuntu-latest
+    timeout-minutes: 3
+    steps:
+    - uses: actions/checkout@v2
+    - uses: actions/setup-node@v2
+      with:
+        node-version: 6
+
+    - name: Install
+      run: npm install
+
+    - name: Tests
+      run: npm test
\ No newline at end of file
diff --git a/.gitignore b/.gitignore
index a734e5b..fa297e8 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,7 @@
 node_modules
 .DS_Store
+*-lock.*
 *.lock
 *.log
+
+/lib
diff --git a/.travis.yml b/.travis.yml
deleted file mode 100644
index 7503aad..0000000
--- a/.travis.yml
+++ /dev/null
@@ -1,4 +0,0 @@
-language: node_js
-node_js:
-  - 6
-  - 4
diff --git a/bench/index.js b/bench/index.js
index 6cef9ad..110d355 100644
--- a/bench/index.js
+++ b/bench/index.js
@@ -1,18 +1,34 @@
-const nopt = require('nopt');
+const { Suite } = require('benchmark');
 const previous = require('mri');
+
+console.log('Load Times:');
+
+console.time('nopt');
+const nopt = require('nopt');
+console.timeEnd('nopt');
+
+console.time('yargs-parser');
 const yargs = require('yargs-parser');
-const { Suite } = require('benchmark');
+console.timeEnd('yargs-parser');
+
+console.time('minimist');
 const minimist = require('minimist');
+console.timeEnd('minimist');
+
+console.time('mri');
 const mri = require('../lib');
+console.timeEnd('mri');
+
 
+console.log('\nBenchmark:');
 const bench = new Suite();
 const args = ['-b', '--bool', '--no-meep', '--multi=baz'];
 
 bench
-	.add('minimist    ', () => minimist(args))
-	.add('mri (prev)  ', () => previous(args))
-	.add('mri         ', () => mri(args))
-	.add('nopt        ', () => nopt(args))
-	.add('yargs-parser', () => yargs(args))
+	.add('minimist     ', () => minimist(args))
+	.add('mri (1.1.1)  ', () => previous(args))
+	.add('mri          ', () => mri(args))
+	.add('nopt         ', () => nopt(args))
+	.add('yargs-parser ', () => yargs(args))
 	.on('cycle', e => console.log(String(e.target)))
 	.run();
diff --git a/bench/package.json b/bench/package.json
index db3996b..f567e3f 100644
--- a/bench/package.json
+++ b/bench/package.json
@@ -1,9 +1,9 @@
 {
   "devDependencies": {
-    "benchmark": "^2.1.4",
-    "minimist": "^1.2.0",
-    "mri": "^0.1.0",
-    "nopt": "^4.0.1",
-    "yargs-parser": "^11.1.1"
+    "benchmark": "2.1.4",
+    "minimist": "1.2.5",
+    "mri": "1.1.1",
+    "nopt": "5.0.0",
+    "yargs-parser": "20.2.9"
   }
 }
diff --git a/index.d.ts b/index.d.ts
new file mode 100644
index 0000000..a46e43d
--- /dev/null
+++ b/index.d.ts
@@ -0,0 +1,21 @@
+type Dict<T> = Record<string, T>;
+type Arrayable<T> = T | T[];
+type Default = Dict<any>;
+
+declare function mri<T=Default>(args?: string[], options?: mri.Options): mri.Argv<T>;
+
+declare namespace mri {
+	export interface Options {
+		boolean?: Arrayable<string>;
+		string?: Arrayable<string>;
+		alias?: Dict<Arrayable<string>>;
+		default?: Dict<any>;
+		unknown?(flag: string): void;
+	}
+
+	export type Argv<T=Default> = T & {
+		_: string[];
+	}
+}
+
+export = mri;
diff --git a/package.json b/package.json
index 8114446..5a224b2 100644
--- a/package.json
+++ b/package.json
@@ -1,23 +1,28 @@
 {
   "name": "mri",
-  "version": "1.1.3",
+  "version": "1.2.0",
   "description": "Quickly scan for CLI flags and arguments",
   "repository": "lukeed/mri",
+  "module": "lib/index.mjs",
   "main": "lib/index.js",
+  "types": "index.d.ts",
   "license": "MIT",
   "files": [
+    "*.d.ts",
     "lib"
   ],
   "author": {
     "name": "Luke Edwards",
     "email": "luke.edwards05@gmail.com",
-    "url": "lukeed.com"
+    "url": "https://lukeed.com"
   },
   "engines": {
     "node": ">=4"
   },
   "scripts": {
+    "build": "bundt",
     "bench": "node bench",
+    "pretest": "npm run build",
     "test": "tape test/*.js | tap-spec"
   },
   "keywords": [
@@ -31,7 +36,8 @@
     "args"
   ],
   "devDependencies": {
-    "tap-spec": "^4.1.1",
-    "tape": "^4.6.3"
+    "bundt": "1.0.2",
+    "tap-spec": "4.1.2",
+    "tape": "4.13.3"
   }
 }
diff --git a/readme.md b/readme.md
index d9cccb6..bff4a04 100644
--- a/readme.md
+++ b/readme.md
@@ -1,4 +1,4 @@
-# mri [![Build Status](https://travis-ci.org/lukeed/mri.svg?branch=master)](https://travis-ci.org/lukeed/mri)
+# mri [![CI](https://github.com/lukeed/mri/workflows/CI/badge.svg?branch=master&event=push)](https://github.com/lukeed/mri/actions) [![licenses](https://licenses.dev/b/npm/mri)](https://licenses.dev/npm/mri)
 
 > Quickly scan for CLI flags and arguments
 
@@ -145,13 +145,20 @@ Once an unknown flag is encountered, parsing will terminate, regardless of your
 
 ## Benchmarks
 
-```
-# Node v10.13.0
+> Running Node.js v10.13.0
 
-minimist      x   324,469 ops/sec ±1.20% (96 runs sampled)
-mri           x 1,611,167 ops/sec ±0.22% (96 runs sampled)
-nopt          x   920,029 ops/sec ±1.13% (97 runs sampled)
-yargs-parser  x    39,542 ops/sec ±1.14% (95 runs sampled)
+```
+Load Times:
+  nopt          3.179ms
+  yargs-parser  2.137ms
+  minimist      0.746ms
+  mri           0.517ms
+
+Benchmark:
+  minimist      x    328,747 ops/sec ±1.09% (89 runs sampled)
+  mri           x  1,622,801 ops/sec ±0.94% (92 runs sampled)
+  nopt          x    888,223 ops/sec ±0.22% (92 runs sampled)
+  yargs-parser  x     30,538 ops/sec ±0.81% (91 runs sampled)
 ```
 
 ## License
diff --git a/lib/index.js b/src/index.js
similarity index 81%
rename from lib/index.js
rename to src/index.js
index b4d8a0a..1a233e5 100644
--- a/lib/index.js
+++ b/src/index.js
@@ -5,14 +5,14 @@ function toArr(any) {
 function toVal(out, key, val, opts) {
 	var x, old=out[key], nxt=(
 		!!~opts.string.indexOf(key) ? (val == null || val === true ? '' : String(val))
-		: !!~opts.boolean.indexOf(key) ? (val === 'false' ? false : val === 'true' || (out._.push((x = +val,x * 0 === 0) ? x : val),!!val))
 		: typeof val === 'boolean' ? val
+		: !!~opts.boolean.indexOf(key) ? (val === 'false' ? false : val === 'true' || (out._.push((x = +val,x * 0 === 0) ? x : val),!!val))
 		: (x = +val,x * 0 === 0) ? x : val
 	);
 	out[key] = old == null ? nxt : (Array.isArray(old) ? old.concat(nxt) : [old, nxt]);
 }
 
-module.exports = function (args, opts) {
+export default function (args, opts) {
 	args = args || [];
 	opts = opts || {};
 
@@ -36,18 +36,26 @@ module.exports = function (args, opts) {
 		}
 	}
 
-	opts.boolean.forEach(key => {
-		opts.boolean = opts.boolean.concat(opts.alias[key] = opts.alias[key] || []);
-	});
+	for (i=opts.boolean.length; i-- > 0;) {
+		arr = opts.alias[opts.boolean[i]] || [];
+		for (j=arr.length; j-- > 0;) opts.boolean.push(arr[j]);
+	}
 
-	opts.string.forEach(key => {
-		opts.string = opts.string.concat(opts.alias[key] = opts.alias[key] || []);
-	});
+	for (i=opts.string.length; i-- > 0;) {
+		arr = opts.alias[opts.string[i]] || [];
+		for (j=arr.length; j-- > 0;) opts.string.push(arr[j]);
+	}
 
 	if (defaults) {
 		for (k in opts.default) {
-			opts.alias[k] = opts.alias[k] || [];
-			(opts[typeof opts.default[k]] || []).push(k);
+			name = typeof opts.default[k];
+			arr = opts.alias[k] = opts.alias[k] || [];
+			if (opts[name] !== void 0) {
+				opts[name].push(k);
+				for (i=0; i < arr.length; i++) {
+					opts[name].push(arr[i]);
+				}
+			}
 		}
 	}
 
diff --git a/test/index.js b/test/index.js
index 88b3738..37abaa5 100644
--- a/test/index.js
+++ b/test/index.js
@@ -93,6 +93,54 @@ test('flag default and alias', t => {
 	t.end();
 });
 
+test('flag default string w/ alias', t => {
+	t.deepEqual(
+		fn(['--arg', '01'], {
+			alias: { a: ['arg'] },
+			default: { arg: '' },
+		}),
+		{ _: [], arg: '01', a: '01' }
+	);
+
+	t.deepEqual(
+		fn(['-a', '01'], {
+			alias: { a: ['arg'] },
+			default: { arg: '' },
+		}),
+		{ _: [], arg: '01', a: '01' }
+	);
+
+	// ---
+
+	t.deepEqual(
+		fn(['-a', '01'], {
+			alias: { arg: ['a'] },
+			default: { a: '' },
+		}),
+		{ _: [], arg: '01', a: '01' }
+	);
+
+	t.deepEqual(
+		fn(['--arg', '01'], {
+			alias: { arg: ['a'] },
+			default: { a: '' },
+		}),
+		{ _: [], arg: '01', a: '01' }
+	);
+
+	// ---
+
+	t.deepEqual(
+		fn(['-a', '01'], {
+			alias: { arg: ['a'] },
+			default: { arg: '' },
+		}),
+		{ _: [], arg: '01', a: '01' }
+	);
+
+	t.end();
+});
+
 // test('newlines in params' , t => {
 //    var args = fn(['-s', "X\nX"])
 //    t.deepEqual(args, { _ : [], s : "X\nX" });
@@ -231,3 +279,52 @@ test('flag default null value', t => {
 	t.same(argv, { foo:true, bar:null, _:[] });
 	t.end();
 });
+
+test('flag boolean with default', t => {
+	const foo = fn(['-t'], { default: { t:true }});
+	t.same(foo, { t:true, _:[] });
+	t.is(typeof foo.t, 'boolean');
+
+	const bar = fn(['-t'], { default: { t:false }});
+	t.same(bar, { t:true, _:[] });
+	t.is(typeof bar.t, 'boolean');
+
+	const baz = fn(['--no-two'], { default: { two:true }});
+	t.same(baz, { two:false, _:[] });
+	t.is(typeof baz.two, 'boolean');
+	t.end();
+});
+
+test('flag boolean with default & alias', t => {
+	const alias = { t: ['tt'], two:['toot'] };
+
+	const foo = fn(['-t'], { alias, default: { t:true }});
+	t.same(foo, { t:true, tt:true, _:[] });
+	t.is(typeof foo.t, 'boolean');
+
+	const bar = fn(['-t'], { alias, default: { t:false }});
+	t.same(bar, { t:true, tt:true, _:[] });
+	t.is(typeof bar.t, 'boolean');
+
+	const baz = fn(['--no-two'], { alias, default: { two:true }});
+	t.same(baz, { two:false, toot:false, _:[] });
+	t.is(typeof baz.two, 'boolean');
+
+	t.end();
+});
+
+test('flag boolean with default string & alias', t => {
+	const foo = fn(['-t'], { default: { t:'hi' }});
+	t.same(foo, { t:'', _:[] });
+	t.is(typeof foo.t, 'string');
+
+	const bar = fn(['-t'], { alias:{ t:'tt' }, default: { t:'boo' }});
+	t.same(bar, { t:'', tt:'', _:[] });
+	t.is(typeof bar.t, 'string');
+
+	// --no-* overrides
+	const baz = fn(['--no-two'], { default: { two:'hi' }});
+	t.same(baz, { two:false, _:[] });
+	t.is(typeof baz.two, 'boolean');
+	t.end();
+});