diff --git a/README.md b/README.md
index 694bde7f..4163cb40 100644
--- a/README.md
+++ b/README.md
@@ -91,7 +91,11 @@ For more details of the JavaScript model, please refer to [JavaScript module REA
 You can also format inputs on your terminal with `budoux` command.
 
 ```shellsession
-$ budoux 本日は晴天です。  # default: japanese
+$ budoux 本日は晴天です。 # default: japanese
+本日は
+晴天です。
+
+$ budoux -l ja 本日は晴天です。
 本日は
 晴天です。
 
@@ -137,7 +141,7 @@ options:
 
 supported languages of `-l`, `--lang`:
 - zh-hans
-- ja-knbc
+- ja
 ```
 
 ## Caveat
diff --git a/budoux/main.py b/budoux/main.py
index 96bf617b..5c70ef72 100644
--- a/budoux/main.py
+++ b/budoux/main.py
@@ -60,14 +60,19 @@ def get_model_langs() -> typing.Dict[str, str]:
   """
   models = glob.glob(
       pkg_resources.resource_filename(__name__, "models") + "/*-*.json")
-  return {model.split(os.sep)[-1][:-5]: model for model in models}
+  langs = {}
+  for model in models:
+    model_name = model.split(os.sep)[-1][:-5]
+    langs[model_name if model_name.startswith('zh-') else model_name[:2]] = model
+  else:
+    return langs
 
 
 def check_lang(lang: str) -> str:
   """Check if given language exists or not.
 
   Args:
-      lang (str): language code (e.g.: 'ja-knbc')
+      lang (str): language code (e.g.: 'ja')
 
   Raises:
       argparse.ArgumentTypeError: Raise if no model for given language exists.
diff --git a/tests/test_main.py b/tests/test_main.py
index cc242a4e..9574c61c 100644
--- a/tests/test_main.py
+++ b/tests/test_main.py
@@ -64,19 +64,32 @@ def test_cmdargs_invalid_json(self) -> None:
 
     self.assertEqual(cm.exception.code, 2)
 
-  def test_cmdargs_invalid_lang(self) -> None:
+  def test_cmdargs_invalid_lang_1(self) -> None:
     cmdargs = ['-l', 'aa']
     with self.assertRaises(SystemExit) as cm:
       main.parse_args(cmdargs)
 
     self.assertEqual(cm.exception.code, 2)
 
+  def test_cmdargs_invalid_lang_2(self) -> None:
+    cmdargs = ['-l', 'ja-knbc']
+    with self.assertRaises(SystemExit) as cm:
+      main.parse_args(cmdargs)
+
+    self.assertEqual(cm.exception.code, 2)
+
   def test_cmdargs_lang_ja(self) -> None:
-    cmdargs = ['-l', 'ja-knbc', '今日はいい天気ですね。']
+    cmdargs = ['-l', 'ja', '今日はいい天気ですね。']
     output = main._main(cmdargs)
 
     self.assertEqual(output, '今日は\nいい\n天気ですね。')
 
+  def test_cmdargs_lang_ja(self) -> None:
+    cmdargs = ['-l', 'zh-hans', '今天天气晴朗。']
+    output = main._main(cmdargs)
+
+    self.assertEqual(output, '今天天气\n晴朗。')
+
 
 class TestTextArguments(unittest.TestCase):