diff --git a/README.md b/README.md
index 09ce36b..a2ba949 100644
--- a/README.md
+++ b/README.md
@@ -10,7 +10,7 @@ koa-locales
 koa locales, i18n solution for koa:
 
 1. All locales resources location on `options.dirs`.
-2. resources file supports: `*.js`, `*.json` and `*.properties`, see [examples](test/locales/).
+2. resources file supports: `*.js`, `*.json`, `*.yml`, `*.yaml` and `*.properties`, see [examples](test/locales/).
 3. One api: `__(key[, value, ...])`.
 4. Auto detect request locale from `query`, `cookie` and `header: Accept-Language`.
 
diff --git a/index.js b/index.js
index 9f3ee2b..52b88e2 100644
--- a/index.js
+++ b/index.js
@@ -9,6 +9,7 @@ const fs = require('fs');
 const path = require('path');
 const ms = require('humanize-ms');
 const assign = require('object-assign');
+const yaml = require('js-yaml');
 
 const DEFAULT_OPTIONS = {
   defaultLocale: 'en-US',
@@ -18,7 +19,7 @@ const DEFAULT_OPTIONS = {
   writeCookie: true,
   cookieMaxAge: '1y',
   dir: undefined,
-  dirs: [ path.join(process.cwd(), 'locales') ],
+  dirs: [path.join(process.cwd(), 'locales')],
   functionName: '__',
 };
 
@@ -62,6 +63,8 @@ module.exports = function (app, options) {
         resource = flattening(require(filepath));
       } else if (name.endsWith('.properties')) {
         resource = ini.parse(fs.readFileSync(filepath, 'utf8'));
+      } else if (name.endsWith('.yml') || name.endsWith('.yaml')) {
+        resource = flattening(yaml.safeLoad(fs.readFileSync(filepath, 'utf8')));
       }
 
       resources[locale] = resources[locale] || {};
@@ -122,7 +125,7 @@ module.exports = function (app, options) {
     // __(locale, key, value1, ...)
     const args = new Array(arguments.length - 1);
     args[0] = text;
-    for(let i = 2; i < arguments.length; i++) {
+    for (let i = 2; i < arguments.length; i++) {
       args[i - 1] = arguments[i];
     }
     return util.format.apply(util, args);
@@ -145,7 +148,7 @@ module.exports = function (app, options) {
     }
     const args = new Array(arguments.length + 1);
     args[0] = locale;
-    for(let i = 0; i < arguments.length; i++) {
+    for (let i = 0; i < arguments.length; i++) {
       args[i + 1] = arguments[i];
     }
     return gettext.apply(this, args);
@@ -293,8 +296,8 @@ function flattening(data) {
 
   const result = {};
 
-  function deepFlat (data, keys) {
-    Object.keys(data).forEach(function(key) {
+  function deepFlat(data, keys) {
+    Object.keys(data).forEach(function (key) {
       const value = data[key];
       const k = keys ? keys + '.' + key : key;
       if (isObject(value)) {
diff --git a/package.json b/package.json
index e0647d0..18e243b 100644
--- a/package.json
+++ b/package.json
@@ -18,6 +18,8 @@
     "debug": "^2.6.0",
     "humanize-ms": "^1.2.0",
     "ini": "^1.3.4",
+    "js-yaml": "^3.13.1",
+    "npminstall": "^3.23.0",
     "object-assign": "^4.1.0"
   },
   "devDependencies": {
diff --git a/test/index.test.js b/test/index.test.js
index e0e9a40..78e4d96 100644
--- a/test/index.test.js
+++ b/test/index.test.js
@@ -15,37 +15,37 @@ describe('koa-locales.test.js', function () {
 
     it('should use default locale: en-US', function (done) {
       request(app.callback())
-      .get('/')
-      .expect({
-        email: 'Email',
-        hello: 'Hello fengmk2, how are you today?',
-        message: 'Hello fengmk2, how are you today? How was your 18.',
-        empty: '',
-        notexists_key: 'key not exists',
-        empty_string: '',
-        empty_value: 'emptyValue',
-        novalue: 'key %s ok',
-        arguments3: '1 2 3',
-        arguments4: '1 2 3 4',
-        arguments5: '1 2 3 4 5',
-        arguments6: '1 2 3 4 5. 6',
-        values: 'foo bar foo bar {2} {100}',
-        object: 'foo bar foo bar {z}',
-        'gender': 'model.user.fields.gender',
-        'name': 'model.user.fields.name',
-      })
-      .expect('Set-Cookie', /^locale=en\-us; path=\/; expires=[^;]+ GMT$/)
-      .expect(200, done);
+        .get('/')
+        .expect({
+          email: 'Email',
+          hello: 'Hello fengmk2, how are you today?',
+          message: 'Hello fengmk2, how are you today? How was your 18.',
+          empty: '',
+          notexists_key: 'key not exists',
+          empty_string: '',
+          empty_value: 'emptyValue',
+          novalue: 'key %s ok',
+          arguments3: '1 2 3',
+          arguments4: '1 2 3 4',
+          arguments5: '1 2 3 4 5',
+          arguments6: '1 2 3 4 5. 6',
+          values: 'foo bar foo bar {2} {100}',
+          object: 'foo bar foo bar {z}',
+          'gender': 'model.user.fields.gender',
+          'name': 'model.user.fields.name',
+        })
+        .expect('Set-Cookie', /^locale=en\-us; path=\/; expires=[^;]+ GMT$/)
+        .expect(200, done);
     });
 
-    it('should not set locale cookie after header sent', function(done) {
+    it('should not set locale cookie after header sent', function (done) {
       request(app.callback())
-      .get('/headerSent')
-      .expect('foo')
-      .expect(200, function(err) {
-        assert(!err, err && err.message);
-        setTimeout(done, 50);
-      });
+        .get('/headerSent')
+        .expect('foo')
+        .expect(200, function (err) {
+          assert(!err, err && err.message);
+          setTimeout(done, 50);
+        });
     });
   });
 
@@ -56,27 +56,27 @@ describe('koa-locales.test.js', function () {
 
     it('should use default locale: en-US', function (done) {
       request(app.callback())
-      .get('/')
-      .expect({
-        email: 'Email',
-        hello: 'Hello fengmk2, how are you today?',
-        message: 'Hello fengmk2, how are you today? How was your 18.',
-        empty: '',
-        notexists_key: 'key not exists',
-        empty_string: '',
-        empty_value: 'emptyValue',
-        novalue: 'key %s ok',
-        arguments3: '1 2 3',
-        arguments4: '1 2 3 4',
-        arguments5: '1 2 3 4 5',
-        arguments6: '1 2 3 4 5. 6',
-        values: 'foo bar foo bar {2} {100}',
-        object: 'foo bar foo bar {z}',
-        'gender': 'model.user.fields.gender',
-        'name': 'model.user.fields.name',
-      })
-      .expect('Set-Cookie', /^locale=en\-us; path=\/; expires=[^;]+; domain=.foo.com$/)
-      .expect(200, done);
+        .get('/')
+        .expect({
+          email: 'Email',
+          hello: 'Hello fengmk2, how are you today?',
+          message: 'Hello fengmk2, how are you today? How was your 18.',
+          empty: '',
+          notexists_key: 'key not exists',
+          empty_string: '',
+          empty_value: 'emptyValue',
+          novalue: 'key %s ok',
+          arguments3: '1 2 3',
+          arguments4: '1 2 3 4',
+          arguments5: '1 2 3 4 5',
+          arguments6: '1 2 3 4 5. 6',
+          values: 'foo bar foo bar {2} {100}',
+          object: 'foo bar foo bar {z}',
+          'gender': 'model.user.fields.gender',
+          'name': 'model.user.fields.name',
+        })
+        .expect('Set-Cookie', /^locale=en\-us; path=\/; expires=[^;]+; domain=.foo.com$/)
+        .expect(200, done);
     });
   });
 
@@ -98,118 +98,7 @@ describe('koa-locales.test.js', function () {
 
     it('should use default locale: en-US', function (done) {
       request(app.callback())
-      .get('/')
-      .expect({
-        email: 'Email',
-        hello: 'Hello fengmk2, how are you today?',
-        message: 'Hello fengmk2, how are you today? How was your 18.',
-        empty: '',
-        notexists_key: 'key not exists',
-        empty_string: '',
-        empty_value: 'emptyValue',
-        novalue: 'key %s ok',
-        arguments3: '1 2 3',
-        arguments4: '1 2 3 4',
-        arguments5: '1 2 3 4 5',
-        arguments6: '1 2 3 4 5. 6',
-        values: 'foo bar foo bar {2} {100}',
-        object: 'foo bar foo bar {z}',
-        'gender': 'model.user.fields.gender',
-        'name': 'model.user.fields.name',
-      })
-      .expect('Set-Cookie', /^locale=en\-us; path=\/; expires=\w+/)
-      .expect(200, done);
-    });
-
-    it('should gettext work on app.__(locale, key, value)', function (done) {
-      request(app.callback())
-      .get('/app_locale_zh')
-      .expect({
-        email: '邮箱1',
-      })
-      .expect(200, done);
-    });
-
-    describe('query.locale', function () {
-      it('should use query locale: zh-CN', function (done) {
-        request(app.callback())
-        .get('/?locale=zh-CN')
-        .expect({
-          email: '邮箱1',
-          hello: 'fengmk2，今天过得如何？',
-          message: 'Hello fengmk2, how are you today? How was your 18.',
-          empty: '',
-          notexists_key: 'key not exists',
-          empty_string: '',
-          empty_value: '',
-          novalue: 'key %s ok',
-          arguments3: '1 2 3',
-          arguments4: '1 2 3 4',
-          arguments5: '1 2 3 4 5',
-          arguments6: '1 2 3 4 5. 6',
-          values: 'foo bar foo bar {2} {100}',
-          object: 'foo bar foo bar {z}',
-          'gender': '性别',
-          'name': '姓名',
-        })
-        .expect('Set-Cookie', /^locale=zh\-cn; path=\/; expires=\w+/)
-        .expect(200, done);
-      });
-
-      it('should use query locale: de on *.properties format', function (done) {
-        request(app.callback())
-        .get('/?locale=de')
-        .expect({
-          email: 'Emailde',
-          hello: 'Hallo fengmk2, wie geht es dir heute?',
-          message: 'Hallo fengmk2, wie geht es dir heute? Wie war dein 18.',
-          empty: '',
-          notexists_key: 'key not exists',
-          empty_string: '',
-          empty_value: 'emptyValue',
-          novalue: 'key %s ok',
-          arguments3: '1 2 3',
-          arguments4: '1 2 3 4',
-          arguments5: '1 2 3 4 5',
-          arguments6: '1 2 3 4 5. 6',
-          values: 'foo bar foo bar {2} {100}',
-          object: 'foo bar foo bar {z}',
-          'gender': 'model.user.fields.gender',
-          'name': 'model.user.fields.name',
-        })
-        .expect('Set-Cookie', /^locale=de; path=\/; expires=\w+/)
-        .expect(200, done);
-      });
-
-      it('should use query locale and change cookie locale', function (done) {
-        request(app.callback())
-        .get('/?locale=zh-CN')
-        .set('cookie', 'locale=zh-TW')
-        .expect({
-          email: '邮箱1',
-          hello: 'fengmk2，今天过得如何？',
-          message: 'Hello fengmk2, how are you today? How was your 18.',
-          empty: '',
-          notexists_key: 'key not exists',
-          empty_string: '',
-          empty_value: '',
-          novalue: 'key %s ok',
-          arguments3: '1 2 3',
-          arguments4: '1 2 3 4',
-          arguments5: '1 2 3 4 5',
-          arguments6: '1 2 3 4 5. 6',
-          values: 'foo bar foo bar {2} {100}',
-          object: 'foo bar foo bar {z}',
-          'gender': '性别',
-          'name': '姓名',
-        })
-        .expect('Set-Cookie', /^locale=zh\-cn; path=\/; expires=\w+/)
-        .expect(200, done);
-      });
-
-      it('should ignore invalid locale value', function (done) {
-        request(app.callback())
-        .get('/?locale=xss')
+        .get('/')
         .expect({
           email: 'Email',
           hello: 'Hello fengmk2, how are you today?',
@@ -230,60 +119,171 @@ describe('koa-locales.test.js', function () {
         })
         .expect('Set-Cookie', /^locale=en\-us; path=\/; expires=\w+/)
         .expect(200, done);
+    });
+
+    it('should gettext work on app.__(locale, key, value)', function (done) {
+      request(app.callback())
+        .get('/app_locale_zh')
+        .expect({
+          email: '邮箱1',
+        })
+        .expect(200, done);
+    });
+
+    describe('query.locale', function () {
+      it('should use query locale: zh-CN', function (done) {
+        request(app.callback())
+          .get('/?locale=zh-CN')
+          .expect({
+            email: '邮箱1',
+            hello: 'fengmk2，今天过得如何？',
+            message: 'Hello fengmk2, how are you today? How was your 18.',
+            empty: '',
+            notexists_key: 'key not exists',
+            empty_string: '',
+            empty_value: '',
+            novalue: 'key %s ok',
+            arguments3: '1 2 3',
+            arguments4: '1 2 3 4',
+            arguments5: '1 2 3 4 5',
+            arguments6: '1 2 3 4 5. 6',
+            values: 'foo bar foo bar {2} {100}',
+            object: 'foo bar foo bar {z}',
+            'gender': '性别',
+            'name': '姓名',
+          })
+          .expect('Set-Cookie', /^locale=zh\-cn; path=\/; expires=\w+/)
+          .expect(200, done);
+      });
+
+      it('should use query locale: de on *.properties format', function (done) {
+        request(app.callback())
+          .get('/?locale=de')
+          .expect({
+            email: 'Emailde',
+            hello: 'Hallo fengmk2, wie geht es dir heute?',
+            message: 'Hallo fengmk2, wie geht es dir heute? Wie war dein 18.',
+            empty: '',
+            notexists_key: 'key not exists',
+            empty_string: '',
+            empty_value: 'emptyValue',
+            novalue: 'key %s ok',
+            arguments3: '1 2 3',
+            arguments4: '1 2 3 4',
+            arguments5: '1 2 3 4 5',
+            arguments6: '1 2 3 4 5. 6',
+            values: 'foo bar foo bar {2} {100}',
+            object: 'foo bar foo bar {z}',
+            'gender': 'model.user.fields.gender',
+            'name': 'model.user.fields.name',
+          })
+          .expect('Set-Cookie', /^locale=de; path=\/; expires=\w+/)
+          .expect(200, done);
+      });
+
+      it('should use query locale and change cookie locale', function (done) {
+        request(app.callback())
+          .get('/?locale=zh-CN')
+          .set('cookie', 'locale=zh-TW')
+          .expect({
+            email: '邮箱1',
+            hello: 'fengmk2，今天过得如何？',
+            message: 'Hello fengmk2, how are you today? How was your 18.',
+            empty: '',
+            notexists_key: 'key not exists',
+            empty_string: '',
+            empty_value: '',
+            novalue: 'key %s ok',
+            arguments3: '1 2 3',
+            arguments4: '1 2 3 4',
+            arguments5: '1 2 3 4 5',
+            arguments6: '1 2 3 4 5. 6',
+            values: 'foo bar foo bar {2} {100}',
+            object: 'foo bar foo bar {z}',
+            'gender': '性别',
+            'name': '姓名',
+          })
+          .expect('Set-Cookie', /^locale=zh\-cn; path=\/; expires=\w+/)
+          .expect(200, done);
+      });
+
+      it('should ignore invalid locale value', function (done) {
+        request(app.callback())
+          .get('/?locale=xss')
+          .expect({
+            email: 'Email',
+            hello: 'Hello fengmk2, how are you today?',
+            message: 'Hello fengmk2, how are you today? How was your 18.',
+            empty: '',
+            notexists_key: 'key not exists',
+            empty_string: '',
+            empty_value: 'emptyValue',
+            novalue: 'key %s ok',
+            arguments3: '1 2 3',
+            arguments4: '1 2 3 4',
+            arguments5: '1 2 3 4 5',
+            arguments6: '1 2 3 4 5. 6',
+            values: 'foo bar foo bar {2} {100}',
+            object: 'foo bar foo bar {z}',
+            'gender': 'model.user.fields.gender',
+            'name': 'model.user.fields.name',
+          })
+          .expect('Set-Cookie', /^locale=en\-us; path=\/; expires=\w+/)
+          .expect(200, done);
       });
 
       it('should use localeAlias', function (done) {
         request(cookieFieldMapApp.callback())
-        .get('/?locale=de-de')
-        .expect({
-          email: 'Emailde',
-          hello: 'Hallo fengmk2, wie geht es dir heute?',
-          message: 'Hallo fengmk2, wie geht es dir heute? Wie war dein 18.',
-          empty: '',
-          notexists_key: 'key not exists',
-          empty_string: '',
-          empty_value: 'emptyValue',
-          novalue: 'key %s ok',
-          arguments3: '1 2 3',
-          arguments4: '1 2 3 4',
-          arguments5: '1 2 3 4 5',
-          arguments6: '1 2 3 4 5. 6',
-          values: 'foo bar foo bar {2} {100}',
-          object: 'foo bar foo bar {z}',
-          'gender': 'model.user.fields.gender',
-          'name': 'model.user.fields.name',
-        })
-        .expect('Set-Cookie', /^locale=de; path=\/; expires=\w+/)
-        .expect(200, done);
+          .get('/?locale=de-de')
+          .expect({
+            email: 'Emailde',
+            hello: 'Hallo fengmk2, wie geht es dir heute?',
+            message: 'Hallo fengmk2, wie geht es dir heute? Wie war dein 18.',
+            empty: '',
+            notexists_key: 'key not exists',
+            empty_string: '',
+            empty_value: 'emptyValue',
+            novalue: 'key %s ok',
+            arguments3: '1 2 3',
+            arguments4: '1 2 3 4',
+            arguments5: '1 2 3 4 5',
+            arguments6: '1 2 3 4 5. 6',
+            values: 'foo bar foo bar {2} {100}',
+            object: 'foo bar foo bar {z}',
+            'gender': 'model.user.fields.gender',
+            'name': 'model.user.fields.name',
+          })
+          .expect('Set-Cookie', /^locale=de; path=\/; expires=\w+/)
+          .expect(200, done);
       });
 
       it('should use query locale and response without set-cookie', function (done) {
         request(appNotWriteCookie.callback())
-        .get('/?locale=zh-CN')
-        .expect({
-          email: '邮箱1',
-          hello: 'fengmk2，今天过得如何？',
-          message: 'Hello fengmk2, how are you today? How was your 18.',
-          empty: '',
-          notexists_key: 'key not exists',
-          empty_string: '',
-          empty_value: '',
-          novalue: 'key %s ok',
-          arguments3: '1 2 3',
-          arguments4: '1 2 3 4',
-          arguments5: '1 2 3 4 5',
-          arguments6: '1 2 3 4 5. 6',
-          values: 'foo bar foo bar {2} {100}',
-          object: 'foo bar foo bar {z}',
-          'gender': '性别',
-          'name': '姓名',
-        })
-        .expect(function(res) {
-          if(res.headers['set-cookie'] || res.headers['Set-Cookie']){
-            throw new Error('should not write cookie');
-          }
-        })
-        .expect(200, done);
+          .get('/?locale=zh-CN')
+          .expect({
+            email: '邮箱1',
+            hello: 'fengmk2，今天过得如何？',
+            message: 'Hello fengmk2, how are you today? How was your 18.',
+            empty: '',
+            notexists_key: 'key not exists',
+            empty_string: '',
+            empty_value: '',
+            novalue: 'key %s ok',
+            arguments3: '1 2 3',
+            arguments4: '1 2 3 4',
+            arguments5: '1 2 3 4 5',
+            arguments6: '1 2 3 4 5. 6',
+            values: 'foo bar foo bar {2} {100}',
+            object: 'foo bar foo bar {z}',
+            'gender': '性别',
+            'name': '姓名',
+          })
+          .expect(function (res) {
+            if (res.headers['set-cookie'] || res.headers['Set-Cookie']) {
+              throw new Error('should not write cookie');
+            }
+          })
+          .expect(200, done);
       });
 
     });
@@ -291,30 +291,30 @@ describe('koa-locales.test.js', function () {
     describe('cookie.locale', function () {
       it('should use cookie locale: zh-CN', function (done) {
         request(app.callback())
-        .get('/?locale=')
-        .set('cookie', 'locale=zh-cn')
-        .expect({
-          email: '邮箱1',
-          hello: 'fengmk2，今天过得如何？',
-          message: 'Hello fengmk2, how are you today? How was your 18.',
-          empty: '',
-          notexists_key: 'key not exists',
-          empty_string: '',
-          empty_value: '',
-          novalue: 'key %s ok',
-          arguments3: '1 2 3',
-          arguments4: '1 2 3 4',
-          arguments5: '1 2 3 4 5',
-          arguments6: '1 2 3 4 5. 6',
-          values: 'foo bar foo bar {2} {100}',
-          object: 'foo bar foo bar {z}',
-          'gender': '性别',
-          'name': '姓名',
-        })
-        .expect(function (res) {
-          assert(!res.headers['set-cookie']);
-        })
-        .expect(200, done);
+          .get('/?locale=')
+          .set('cookie', 'locale=zh-cn')
+          .expect({
+            email: '邮箱1',
+            hello: 'fengmk2，今天过得如何？',
+            message: 'Hello fengmk2, how are you today? How was your 18.',
+            empty: '',
+            notexists_key: 'key not exists',
+            empty_string: '',
+            empty_value: '',
+            novalue: 'key %s ok',
+            arguments3: '1 2 3',
+            arguments4: '1 2 3 4',
+            arguments5: '1 2 3 4 5',
+            arguments6: '1 2 3 4 5. 6',
+            values: 'foo bar foo bar {2} {100}',
+            object: 'foo bar foo bar {z}',
+            'gender': '性别',
+            'name': '姓名',
+          })
+          .expect(function (res) {
+            assert(!res.headers['set-cookie']);
+          })
+          .expect(200, done);
       });
     });
 
@@ -323,154 +323,154 @@ describe('koa-locales.test.js', function () {
         done = pedding(3, done);
 
         request(app.callback())
-        .get('/?locale=')
-        .set('Accept-Language', 'zh-CN')
-        .expect({
-          email: '邮箱1',
-          hello: 'fengmk2，今天过得如何？',
-          message: 'Hello fengmk2, how are you today? How was your 18.',
-          empty: '',
-          notexists_key: 'key not exists',
-          empty_string: '',
-          empty_value: '',
-          novalue: 'key %s ok',
-          arguments3: '1 2 3',
-          arguments4: '1 2 3 4',
-          arguments5: '1 2 3 4 5',
-          arguments6: '1 2 3 4 5. 6',
-          values: 'foo bar foo bar {2} {100}',
-          object: 'foo bar foo bar {z}',
-          'gender': '性别',
-          'name': '姓名',
-        })
-        .expect('Set-Cookie', /^locale=zh\-cn; path=\/; expires=\w+/)
-        .expect(200, done);
+          .get('/?locale=')
+          .set('Accept-Language', 'zh-CN')
+          .expect({
+            email: '邮箱1',
+            hello: 'fengmk2，今天过得如何？',
+            message: 'Hello fengmk2, how are you today? How was your 18.',
+            empty: '',
+            notexists_key: 'key not exists',
+            empty_string: '',
+            empty_value: '',
+            novalue: 'key %s ok',
+            arguments3: '1 2 3',
+            arguments4: '1 2 3 4',
+            arguments5: '1 2 3 4 5',
+            arguments6: '1 2 3 4 5. 6',
+            values: 'foo bar foo bar {2} {100}',
+            object: 'foo bar foo bar {z}',
+            'gender': '性别',
+            'name': '姓名',
+          })
+          .expect('Set-Cookie', /^locale=zh\-cn; path=\/; expires=\w+/)
+          .expect(200, done);
 
         request(app.callback())
-        .get('/?locale=')
-        .set('Accept-Language', 'zh-CN,zh;q=0.8')
-        .expect({
-          email: '邮箱1',
-          hello: 'fengmk2，今天过得如何？',
-          message: 'Hello fengmk2, how are you today? How was your 18.',
-          empty: '',
-          notexists_key: 'key not exists',
-          empty_string: '',
-          empty_value: '',
-          novalue: 'key %s ok',
-          arguments3: '1 2 3',
-          arguments4: '1 2 3 4',
-          arguments5: '1 2 3 4 5',
-          arguments6: '1 2 3 4 5. 6',
-          values: 'foo bar foo bar {2} {100}',
-          object: 'foo bar foo bar {z}',
-          'gender': '性别',
-          'name': '姓名',
-        })
-        .expect('Set-Cookie', /^locale=zh\-cn; path=\/; expires=\w+/)
-        .expect(200, done);
+          .get('/?locale=')
+          .set('Accept-Language', 'zh-CN,zh;q=0.8')
+          .expect({
+            email: '邮箱1',
+            hello: 'fengmk2，今天过得如何？',
+            message: 'Hello fengmk2, how are you today? How was your 18.',
+            empty: '',
+            notexists_key: 'key not exists',
+            empty_string: '',
+            empty_value: '',
+            novalue: 'key %s ok',
+            arguments3: '1 2 3',
+            arguments4: '1 2 3 4',
+            arguments5: '1 2 3 4 5',
+            arguments6: '1 2 3 4 5. 6',
+            values: 'foo bar foo bar {2} {100}',
+            object: 'foo bar foo bar {z}',
+            'gender': '性别',
+            'name': '姓名',
+          })
+          .expect('Set-Cookie', /^locale=zh\-cn; path=\/; expires=\w+/)
+          .expect(200, done);
 
         request(app.callback())
-        .get('/?locale=')
-        .set('Accept-Language', 'en;q=0.8, es, zh_CN')
-        .expect({
-          email: '邮箱1',
-          hello: 'fengmk2，今天过得如何？',
-          message: 'Hello fengmk2, how are you today? How was your 18.',
-          empty: '',
-          notexists_key: 'key not exists',
-          empty_string: '',
-          empty_value: '',
-          novalue: 'key %s ok',
-          arguments3: '1 2 3',
-          arguments4: '1 2 3 4',
-          arguments5: '1 2 3 4 5',
-          arguments6: '1 2 3 4 5. 6',
-          values: 'foo bar foo bar {2} {100}',
-          object: 'foo bar foo bar {z}',
-          'gender': '性别',
-          'name': '姓名',
-        })
-        .expect('Set-Cookie', /^locale=zh\-cn; path=\/; expires=\w+/)
-        .expect(200, done);
+          .get('/?locale=')
+          .set('Accept-Language', 'en;q=0.8, es, zh_CN')
+          .expect({
+            email: '邮箱1',
+            hello: 'fengmk2，今天过得如何？',
+            message: 'Hello fengmk2, how are you today? How was your 18.',
+            empty: '',
+            notexists_key: 'key not exists',
+            empty_string: '',
+            empty_value: '',
+            novalue: 'key %s ok',
+            arguments3: '1 2 3',
+            arguments4: '1 2 3 4',
+            arguments5: '1 2 3 4 5',
+            arguments6: '1 2 3 4 5. 6',
+            values: 'foo bar foo bar {2} {100}',
+            object: 'foo bar foo bar {z}',
+            'gender': '性别',
+            'name': '姓名',
+          })
+          .expect('Set-Cookie', /^locale=zh\-cn; path=\/; expires=\w+/)
+          .expect(200, done);
       });
 
       it('should work with "Accept-Language: " header', function (done) {
         request(app.callback())
-        .get('/?locale=')
-        .set('Accept-Language', '')
-        .expect({
-          email: 'Email',
-          hello: 'Hello fengmk2, how are you today?',
-          message: 'Hello fengmk2, how are you today? How was your 18.',
-          empty: '',
-          notexists_key: 'key not exists',
-          empty_string: '',
-          empty_value: 'emptyValue',
-          novalue: 'key %s ok',
-          arguments3: '1 2 3',
-          arguments4: '1 2 3 4',
-          arguments5: '1 2 3 4 5',
-          arguments6: '1 2 3 4 5. 6',
-          values: 'foo bar foo bar {2} {100}',
-          object: 'foo bar foo bar {z}',
-          'gender': 'model.user.fields.gender',
-          'name': 'model.user.fields.name',
-        })
-        .expect('Set-Cookie', /^locale=en\-us; path=\/; expires=\w+/)
-        .expect(200, done);
+          .get('/?locale=')
+          .set('Accept-Language', '')
+          .expect({
+            email: 'Email',
+            hello: 'Hello fengmk2, how are you today?',
+            message: 'Hello fengmk2, how are you today? How was your 18.',
+            empty: '',
+            notexists_key: 'key not exists',
+            empty_string: '',
+            empty_value: 'emptyValue',
+            novalue: 'key %s ok',
+            arguments3: '1 2 3',
+            arguments4: '1 2 3 4',
+            arguments5: '1 2 3 4 5',
+            arguments6: '1 2 3 4 5. 6',
+            values: 'foo bar foo bar {2} {100}',
+            object: 'foo bar foo bar {z}',
+            'gender': 'model.user.fields.gender',
+            'name': 'model.user.fields.name',
+          })
+          .expect('Set-Cookie', /^locale=en\-us; path=\/; expires=\w+/)
+          .expect(200, done);
       });
 
       it('should work with "Accept-Language: en"', function (done) {
         request(app.callback())
-        .get('/')
-        .set('Accept-Language', 'en')
-        .expect({
-          email: 'Email',
-          hello: 'Hello fengmk2, how are you today?',
-          message: 'Hello fengmk2, how are you today? How was your 18.',
-          empty: '',
-          notexists_key: 'key not exists',
-          empty_string: '',
-          empty_value: 'emptyValue',
-          novalue: 'key %s ok',
-          arguments3: '1 2 3',
-          arguments4: '1 2 3 4',
-          arguments5: '1 2 3 4 5',
-          arguments6: '1 2 3 4 5. 6',
-          values: 'foo bar foo bar {2} {100}',
-          object: 'foo bar foo bar {z}',
-          'gender': 'model.user.fields.gender',
-          'name': 'model.user.fields.name',
-        })
-        .expect('Set-Cookie', /^locale=en\-us; path=\/; expires=\w+/)
-        .expect(200, done);
+          .get('/')
+          .set('Accept-Language', 'en')
+          .expect({
+            email: 'Email',
+            hello: 'Hello fengmk2, how are you today?',
+            message: 'Hello fengmk2, how are you today? How was your 18.',
+            empty: '',
+            notexists_key: 'key not exists',
+            empty_string: '',
+            empty_value: 'emptyValue',
+            novalue: 'key %s ok',
+            arguments3: '1 2 3',
+            arguments4: '1 2 3 4',
+            arguments5: '1 2 3 4 5',
+            arguments6: '1 2 3 4 5. 6',
+            values: 'foo bar foo bar {2} {100}',
+            object: 'foo bar foo bar {z}',
+            'gender': 'model.user.fields.gender',
+            'name': 'model.user.fields.name',
+          })
+          .expect('Set-Cookie', /^locale=en\-us; path=\/; expires=\w+/)
+          .expect(200, done);
       });
 
       it('should work with "Accept-Language: de-de" by localeAlias', function (done) {
         request(cookieFieldMapApp.callback())
-        .get('/')
-        .set('Accept-Language', 'ja,de-de;q=0.8')
-        .expect({
-          email: 'Emailde',
-          hello: 'Hallo fengmk2, wie geht es dir heute?',
-          message: 'Hallo fengmk2, wie geht es dir heute? Wie war dein 18.',
-          empty: '',
-          notexists_key: 'key not exists',
-          empty_string: '',
-          empty_value: 'emptyValue',
-          novalue: 'key %s ok',
-          arguments3: '1 2 3',
-          arguments4: '1 2 3 4',
-          arguments5: '1 2 3 4 5',
-          arguments6: '1 2 3 4 5. 6',
-          values: 'foo bar foo bar {2} {100}',
-          object: 'foo bar foo bar {z}',
-          'gender': 'model.user.fields.gender',
-          'name': 'model.user.fields.name',
-        })
-        .expect('Set-Cookie', /^locale=de; path=\/; expires=\w+/)
-        .expect(200, done);
+          .get('/')
+          .set('Accept-Language', 'ja,de-de;q=0.8')
+          .expect({
+            email: 'Emailde',
+            hello: 'Hallo fengmk2, wie geht es dir heute?',
+            message: 'Hallo fengmk2, wie geht es dir heute? Wie war dein 18.',
+            empty: '',
+            notexists_key: 'key not exists',
+            empty_string: '',
+            empty_value: 'emptyValue',
+            novalue: 'key %s ok',
+            arguments3: '1 2 3',
+            arguments4: '1 2 3 4',
+            arguments5: '1 2 3 4 5',
+            arguments6: '1 2 3 4 5. 6',
+            values: 'foo bar foo bar {2} {100}',
+            object: 'foo bar foo bar {z}',
+            'gender': 'model.user.fields.gender',
+            'name': 'model.user.fields.name',
+          })
+          .expect('Set-Cookie', /^locale=de; path=\/; expires=\w+/)
+          .expect(200, done);
       });
 
       it('should mock acceptsLanguages return string', function (done) {
@@ -478,27 +478,56 @@ describe('koa-locales.test.js', function () {
           return 'zh-TW';
         });
         request(app.callback())
-        .get('/?locale=')
-        .expect({
-          email: '郵箱',
-          hello: 'fengmk2，今天過得如何？',
-          message: 'Hello fengmk2, how are you today? How was your 18.',
-          empty: '',
-          notexists_key: 'key not exists',
-          empty_string: '',
-          empty_value: '',
-          novalue: 'key %s ok',
-          arguments3: '1 2 3',
-          arguments4: '1 2 3 4',
-          arguments5: '1 2 3 4 5',
-          arguments6: '1 2 3 4 5. 6',
-          values: 'foo bar foo bar {2} {100}',
-          object: 'foo bar foo bar {z}',
-          'gender': '性別',
-          'name': '姓名',
-        })
-        .expect('Set-Cookie', /^locale=zh\-tw; path=\/; expires=\w+/)
-        .expect(200, done);
+          .get('/?locale=')
+          .expect({
+            email: '郵箱',
+            hello: 'fengmk2，今天過得如何？',
+            message: 'Hello fengmk2, how are you today? How was your 18.',
+            empty: '',
+            notexists_key: 'key not exists',
+            empty_string: '',
+            empty_value: '',
+            novalue: 'key %s ok',
+            arguments3: '1 2 3',
+            arguments4: '1 2 3 4',
+            arguments5: '1 2 3 4 5',
+            arguments6: '1 2 3 4 5. 6',
+            values: 'foo bar foo bar {2} {100}',
+            object: 'foo bar foo bar {z}',
+            'gender': '性別',
+            'name': '姓名',
+          })
+          .expect('Set-Cookie', /^locale=zh\-tw; path=\/; expires=\w+/)
+          .expect(200, done);
+      });
+
+      it('should mock acceptsLanguages return string', function (done) {
+        mm(app.request, 'acceptsLanguages', function () {
+          return 'fr';
+        });
+        request(app.callback())
+          .get('/?locale=fr')
+          .set('Accept-Language', 'fr;q=0.8, fr, fr')
+          .expect({
+            email: 'le email',
+            hello: 'fengmk2, Comment allez-vous',
+            message: 'Hello fengmk2, how are you today? How was your 18.',
+            empty: '',
+            notexists_key: 'key not exists',
+            empty_string: '',
+            empty_value: '',
+            novalue: 'key %s ok',
+            arguments3: '1 2 3',
+            arguments4: '1 2 3 4',
+            arguments5: '1 2 3 4 5',
+            arguments6: '1 2 3 4 5. 6',
+            values: 'foo bar foo bar {2} {100}',
+            object: 'foo bar foo bar {z}',
+            gender: 'le sexe',
+            name: 'prénom',
+          })
+          .expect('Set-Cookie', /^locale=fr; path=\/; expires=\w+/)
+          .expect(200, done);
       });
 
       it('should mock acceptsLanguages return null', function (done) {
@@ -506,31 +535,31 @@ describe('koa-locales.test.js', function () {
           return null;
         });
         request(app.callback())
-        .get('/?locale=')
-        .expect({
-          email: 'Email',
-          hello: 'Hello fengmk2, how are you today?',
-          message: 'Hello fengmk2, how are you today? How was your 18.',
-          empty: '',
-          notexists_key: 'key not exists',
-          empty_string: '',
-          empty_value: 'emptyValue',
-          novalue: 'key %s ok',
-          arguments3: '1 2 3',
-          arguments4: '1 2 3 4',
-          arguments5: '1 2 3 4 5',
-          arguments6: '1 2 3 4 5. 6',
-          values: 'foo bar foo bar {2} {100}',
-          object: 'foo bar foo bar {z}',
-          'gender': 'model.user.fields.gender',
-          'name': 'model.user.fields.name',
-        })
-        .expect('Set-Cookie', /^locale=en\-us; path=\/; expires=\w+/)
-        .expect(200, done);
+          .get('/?locale=')
+          .expect({
+            email: 'Email',
+            hello: 'Hello fengmk2, how are you today?',
+            message: 'Hello fengmk2, how are you today? How was your 18.',
+            empty: '',
+            notexists_key: 'key not exists',
+            empty_string: '',
+            empty_value: 'emptyValue',
+            novalue: 'key %s ok',
+            arguments3: '1 2 3',
+            arguments4: '1 2 3 4',
+            arguments5: '1 2 3 4 5',
+            arguments6: '1 2 3 4 5. 6',
+            values: 'foo bar foo bar {2} {100}',
+            object: 'foo bar foo bar {z}',
+            'gender': 'model.user.fields.gender',
+            'name': 'model.user.fields.name',
+          })
+          .expect('Set-Cookie', /^locale=en\-us; path=\/; expires=\w+/)
+          .expect(200, done);
       });
     });
 
-    describe('__getLocale and __getLocaleOrigin', function() {
+    describe('__getLocale and __getLocaleOrigin', function () {
       it('should __getLocale and __getLocaleOrigin from cookie', function () {
         return request(app.callback())
           .get('/origin')
@@ -558,7 +587,7 @@ describe('koa-locales.test.js', function () {
       });
     });
 
-    describe('__setLocale', function() {
+    describe('__setLocale', function () {
       it('should set locale and cookie', function () {
         return request(app.callback())
           .get('/set')
@@ -606,7 +635,7 @@ function createApp(options) {
     if (this.url === '/headerSent') {
       this.body = 'foo';
       const that = this;
-      setTimeout(function() {
+      setTimeout(function () {
         that[fname]('Email');
       }, 10);
       return;
@@ -628,7 +657,7 @@ function createApp(options) {
       arguments5: this[fname]('%s %s %s %s %s', 1, 2, 3, 4, 5),
       arguments6: this[fname]('%s %s %s %s %s.', 1, 2, 3, 4, 5, 6),
       values: this[fname]('{0} {1} {0} {1} {2} {100}', ['foo', 'bar']),
-      object: this[fname]('{foo} {bar} {foo} {bar} {z}', {foo: 'foo', bar: 'bar'}),
+      object: this[fname]('{foo} {bar} {foo} {bar} {z}', { foo: 'foo', bar: 'bar' }),
     };
   });
 
diff --git a/test/locales/fr.yml b/test/locales/fr.yml
new file mode 100644
index 0000000..c206209
--- /dev/null
+++ b/test/locales/fr.yml
@@ -0,0 +1,8 @@
+Email: "le email"
+emptyValue: ""
+Hello %s, how are you today?: "%s, Comment allez-vous"
+model:
+  user:
+    fields:
+      name: "prénom"
+      gender: "le sexe"
\ No newline at end of file