diff --git a/index.js b/index.js
index 43cdfbf..4ac85e6 100644
--- a/index.js
+++ b/index.js
@@ -9,6 +9,7 @@
 
 var fs = require('fs');
 var path = require('path');
+var expand = require('expand-tilde');
 var exists = require('fs-exists-sync');
 var extend = require('extend-shallow');
 var configPath = require('git-config-path');
@@ -33,23 +34,36 @@ var ini = require('ini');
 function parse(options, cb) {
   if (typeof options === 'function') {
     cb = options;
-    options = {};
+    options = null;
   }
 
   if (typeof cb !== 'function') {
-    throw new TypeError('parse-git-config async expects a callback function.');
+    throw new TypeError('expected callback to be a function');
   }
 
-  options = options || {};
-  var filepath = parse.resolve(options);
+  var filepath = parse.resolveConfigPath(options);
+  if (filepath === null) {
+    cb();
+    return;
+  }
 
   fs.stat(filepath, function(err, stat) {
-    if (err) return cb(err);
+    if (err) {
+      cb(err);
+      return;
+    }
 
     fs.readFile(filepath, 'utf8', function(err, str) {
-      if (err) return cb(err);
-      var parsed = ini.parse(str);
-      cb(null, parsed);
+      if (err) {
+        cb(err);
+        return;
+      }
+
+      if (options && options.include === true) {
+        str = injectInclude(str, path.resolve(path.dirname(filepath)));
+      }
+
+      cb(null, ini.parse(str));
     });
   });
 }
@@ -69,12 +83,17 @@ function parse(options, cb) {
  */
 
 parse.sync = function parseSync(options) {
-  options = options || {};
-  var filepath = parse.resolve(options);
-
+  var filepath = parse.resolveConfigPath(options);
   if (filepath && exists(filepath)) {
-    var str = fs.readFileSync(filepath, 'utf8');
-    return ini.parse(str);
+    var input = fs.readFileSync(filepath, 'utf8');
+
+    if (options && options.include === true) {
+      var cwd = path.resolve(path.dirname(filepath));
+      var str = injectInclude(input, cwd);
+      return ini.parse(str);
+    }
+
+    return ini.parse(input);
   }
   return {};
 };
@@ -83,15 +102,23 @@ parse.sync = function parseSync(options) {
  * Resolve the git config path
  */
 
-parse.resolve = function resolve(options) {
+parse.resolveConfigPath = function(options) {
   if (typeof options === 'string') {
     options = { type: options };
   }
   var opts = extend({cwd: process.cwd()}, options);
-  var fp = opts.path || configPath(opts.type);
+  var fp = opts.path ? expand(opts.path) : configPath(opts.type);
   return fp ? path.resolve(opts.cwd, fp) : null;
 };
 
+/**
+ * Deprecated: use `.resolveConfigPath` instead
+ */
+
+parse.resolve = function(options) {
+  return parse.resolveConfigPath(options);
+};
+
 /**
  * Returns an object with only the properties that had ini-style keys
  * converted to objects (example below).
@@ -118,6 +145,38 @@ parse.keys = function parseKeys(config) {
   return res;
 };
 
+function injectInclude(input, cwd) {
+  var pathRegex = /^\s*path\s*=\s*/;
+  var lines = input.split('\n');
+  var len = lines.length;
+  var filepath = '';
+  var res = [];
+
+  for (var i = 0; i < len; i++) {
+    var line = lines[i];
+    var n = i;
+
+    if (line.indexOf('[include]') === 0) {
+      while (n < len && !pathRegex.test(filepath)) {
+        filepath = lines[++n];
+      }
+
+      if (!filepath) {
+        return input;
+      }
+
+      filepath = filepath.replace(pathRegex, '');
+      var fp = path.resolve(cwd, expand(filepath));
+      res.push(fs.readFileSync(fp));
+
+    } else {
+      res.push(line);
+    }
+  }
+
+  return res.join('\n');
+}
+
 /**
  * Expose `parse`
  */
diff --git a/package.json b/package.json
index b90f9f1..d595282 100644
--- a/package.json
+++ b/package.json
@@ -25,15 +25,16 @@
     "test": "mocha"
   },
   "dependencies": {
-    "extend-shallow": "^2.0.1",
+    "expand-tilde": "^2.0.2",
+    "extend-shallow": "^3.0.2",
     "fs-exists-sync": "^0.1.0",
     "git-config-path": "^1.0.1",
-    "ini": "^1.3.4"
+    "ini": "^1.3.5"
   },
   "devDependencies": {
-    "gulp-format-md": "^0.1.11",
-    "homedir-polyfill": "^1.0.1",
-    "mocha": "^3.2.0"
+    "gulp-format-md": "^1.0.0",
+    "mocha": "^3.5.3",
+    "homedir-polyfill": "^1.0.1"
   },
   "keywords": [
     "config",
diff --git a/test/expected/_gitconfig.js b/test/expected/_gitconfig.js
new file mode 100644
index 0000000..70dd302
--- /dev/null
+++ b/test/expected/_gitconfig.js
@@ -0,0 +1,122 @@
+module.exports = {
+  user: {
+    email: 'email',
+    name: 'name',
+    signingkey: 'https://help.github.com/articles/generating-a-new-gpg-key/'
+  },
+  github: {
+    user: 'name',
+    token: 'https://github.com/settings/tokens'
+  },
+  commit: {
+    gpgsign: true
+  },
+  tag: {
+    gpgsign: true,
+    path: '_gitconfig.local',
+    sort: 'version:refname'
+  },
+  core: {
+    legacyheaders: false,
+    quotepath: false,
+    trustctime: false,
+    precomposeunicode: false,
+    pager: 'cat',
+    logAllRefUpdates: true,
+    excludesfile: '~/.gitignore'
+  },
+  repack: {
+    usedeltabaseoffset: true
+  },
+  merge: {
+    log: true,
+    conflictstyle: 'diff3'
+  },
+  apply: {
+    whitespace: 'fix'
+  },
+  help: {
+    autocorrect: '1'
+  },
+  rerere: {
+    enabled: true
+  },
+  color: {
+    diff: 'auto',
+    status: 'auto',
+    branch: 'auto',
+    interactive: 'auto',
+    ui: 'always'
+  },
+  'color "diff"': {
+    meta: 'yellow bold',
+    frag: 'magenta',
+    plain: 'white bold',
+    old: 'red bold',
+    new: 'green bold',
+    commit: 'yellow bold',
+    func: 'green dim',
+    whitespace: 'red reverse'
+  },
+  'color "status"': {
+    added: 'yellow',
+    changed: 'green',
+    untracked: 'cyan'
+  },
+  'color "branch"': {
+    current: 'yellow reverse',
+    local: 'yellow',
+    remote: 'green'
+  },
+  diff: {
+    renames: 'copies',
+    algorithm: 'patience',
+    compactionHeuristic: true,
+    wsErrorHighlight: 'all'
+  },
+  'diff "bin"': {
+    textconv: 'hexdump -v -C'
+  },
+  credential: {
+    helper: 'store'
+  },
+  status: {
+    relativePaths: true,
+    showUntrackedFiles: 'no'
+  },
+  pull: {
+    rebase: true
+  },
+  push: {
+    default: 'current',
+    followTags: true
+  },
+  alias: {
+    a: 'commit --amend',
+    c: 'commit -am',
+    d: '!git diff --exit-code && git diff --cached',
+    dif: 'diff',
+    git: '!exec git',
+    p: 'push -u',
+    r: 'reset --soft HEAD~1',
+    s: 'status',
+    sc: 'clone --depth=1',
+    l: 'log --graph --pretty=format:\'%Cred%h%Creset -%C(yellow)%d%Creset %s %Cgreen(%cr) %C(bold blue)<%an>%Creset\' --abbrev-commit -n 15'
+  },
+  'remote "origin"': {
+    fetch: '+refs/tags/*:refs/tags/*'
+  },
+  branch: {
+    autosetupmerge: 'always',
+    autosetuprebase: 'always'
+  },
+  http: {
+    sslverify: false
+  },
+  submodule: {
+    fetchJobs: '0'
+  },
+  fetch: {
+    prune: true
+  }
+};
diff --git a/test/fixtures/_gitconfig b/test/fixtures/_gitconfig
new file mode 100644
index 0000000..7b999ac
--- /dev/null
+++ b/test/fixtures/_gitconfig
@@ -0,0 +1,86 @@
+[include]
+  path = _gitconfig.local
+[core]
+  legacyheaders = false
+  quotepath = false
+  trustctime = false
+  precomposeunicode = false
+  pager = cat
+  logAllRefUpdates = true
+  excludesfile = ~/.gitignore
+[repack]
+  usedeltabaseoffset = true
+[merge]
+  log = true
+  conflictstyle = diff3
+[apply]
+  whitespace = fix
+[help]
+  autocorrect = 1
+[rerere]
+  enabled = true
+[color]
+  diff = auto
+  status = auto
+  branch = auto
+  interactive = auto
+  ui = always
+[color "diff"]
+  meta = yellow bold
+  frag = magenta
+  plain = white bold
+  old = red bold
+  new = green bold
+  commit = yellow bold
+  func = green dim
+  whitespace = red reverse
+[color "status"]
+  added = yellow
+  changed = green
+  untracked = cyan
+[color "branch"]
+  current = yellow reverse
+  local = yellow
+  remote = green
+[diff]
+  renames = copies
+  algorithm = patience
+  compactionHeuristic = true
+  wsErrorHighlight = all
+[diff "bin"]
+  textconv = hexdump -v -C
+[credential]
+  helper = store
+[status]
+  relativePaths = true
+  showUntrackedFiles = no
+[pull]
+  rebase = true
+[push]
+  default = current
+  followTags = true
+[alias]
+  a = commit --amend
+  c = commit -am
+  d = !git diff --exit-code && git diff --cached
+  dif = diff
+  git = !exec git
+  p = push -u
+  r = reset --soft HEAD~1
+  s = status
+  sc = clone --depth=1
+  l = log --graph --pretty=format:'%Cred%h%Creset -%C(yellow)%d%Creset %s %Cgreen(%cr) %C(bold blue)<%an>%Creset' --abbrev-commit -n 15
+[remote "origin"]
+  fetch = +refs/pr/*/head:refs/remotes/origin/pr/*
+  fetch = +refs/tags/*:refs/tags/*
+[branch]
+  autosetupmerge = always
+  autosetuprebase = always
+[http]
+  sslverify = false
+[submodule]
+  fetchJobs = 0
+[fetch]
+  prune = true
+[tag]
+  sort = version:refname
diff --git a/test/fixtures/_gitconfig.local b/test/fixtures/_gitconfig.local
new file mode 100644
index 0000000..afa9a19
--- /dev/null
+++ b/test/fixtures/_gitconfig.local
@@ -0,0 +1,11 @@
+[user]
+  email = email
+  name = name
+  signingkey = https://help.github.com/articles/generating-a-new-gpg-key/
+[github]
+  user = name
+  token = https://github.com/settings/tokens
+[commit]
+  gpgsign = true
+[tag]
+  gpgsign = true
\ No newline at end of file
diff --git a/test.js b/test/test.js
similarity index 64%
rename from test.js
rename to test/test.js
index 1f63fc3..c00c66c 100644
--- a/test.js
+++ b/test/test.js
@@ -1,7 +1,7 @@
 /*!
  * parse-git-config <https://github.com/jonschlinkert/parse-git-config>
  *
- * Copyright (c) 2015 Jon Schlinkert.
+ * Copyright (c) 2015-2018 Jon Schlinkert.
  * Licensed under the MIT license.
  */
 
@@ -9,11 +9,16 @@
 
 require('mocha');
 var isTravis = process.env.TRAVIS || process.env.CLI;
+var fs = require('fs');
 var os = require('os');
 var assert = require('assert');
 var path = require('path');
 var homedir = require('homedir-polyfill');
-var parse = require('./');
+var parse = require('..');
+
+function read(filepath) {
+  return fs.readFileSync(path.join(__dirname, filepath), 'utf8');
+}
 
 describe('sync:', function() {
   it('should return an object', function() {
@@ -22,14 +27,10 @@ describe('sync:', function() {
 });
 
 describe('async:', function() {
-  it('should throw a callback is not passed:', function(cb) {
-    try {
+  it('should throw a callback is not passed:', function() {
+    assert.throws(function() {
       parse();
-      cb(new Error('expected an error'));
-    } catch (err) {
-      assert.equal(err.message, 'parse-git-config async expects a callback function.');
-      cb();
-    }
+    }, /expected/);
   });
 
   it('should parse .git/config', function(cb) {
@@ -40,8 +41,18 @@ describe('async:', function() {
     });
   });
 
+  it('should include other config sources', function() {
+    var fp = path.join(__dirname, 'fixtures/_gitconfig');
+
+    parse({ path: fp, include: true }, function(err, config) {
+      assert(!err);
+      assert.deepEqual(config, require('./expected/_gitconfig.js'));
+      cb();
+    });
+  });
+
   it('should throw an error when .git/config does not exist:', function(cb) {
-    parse({path: 'foo'}, function(err, config) {
+    parse({ path: 'foo' }, function(err, config) {
       assert(err instanceof Error);
       assert(/ENOENT.*parse-git-config/.test(err.message));
       cb();
@@ -56,11 +67,17 @@ describe('resolve:', function() {
 
   it('should allow override path', function() {
     var fp = path.resolve(homedir(), '.gitconfig');
-    assert.equal(parse.resolve({path: fp}), fp);
+    assert.equal(parse.resolve({ path: fp }), fp);
+  });
+
+  it('should include other config sources', function() {
+    var fp = path.join(__dirname, 'fixtures/_gitconfig');
+    var actual = parse.sync({ path: fp, include: true });
+    assert.deepEqual(actual, require('./expected/_gitconfig.js'));
   });
 
   it('should resolve relative path to cwd', function() {
-    assert.equal(parse.resolve({path: '.config'}), path.resolve(process.cwd(), '.config'));
+    assert.equal(parse.resolve({ path: '.config' }), path.resolve(process.cwd(), '.config'));
   });
 
   it('should resolve relative path to the global git config when `global` is passed', function() {
@@ -69,7 +86,7 @@ describe('resolve:', function() {
   });
 
   it('should allow override of cwd', function() {
-    var actual = parse.resolve({path: '.config', cwd: '/opt/config'});
+    var actual = parse.resolve({ path: '.config', cwd: '/opt/config' });
     assert.equal(actual, path.resolve('/opt/config/.config'));
   });
 });