diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5007db3..c1db751 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,7 +1,7 @@
 # Changelog
 
-## [0.10.0] 06-06-2022
+## [0.10.1] 25-07-2022
 
-### NEW
+### FIX
 
-- Adding a new `Password` type that will hide the default value when printing help with the Rich Formatter.
+- Fix parsing issue of `Optional` types.
diff --git a/piou/utils.py b/piou/utils.py
index 296c33a..727c9b5 100644
--- a/piou/utils.py
+++ b/piou/utils.py
@@ -12,7 +12,7 @@
 from pathlib import Path
 from typing import (
     Any, Optional, get_args, get_origin, get_type_hints,
-    Literal, TypeVar, Generic, Callable
+    Literal, TypeVar, Generic, Callable, Union
 )
 from uuid import UUID
 
@@ -29,36 +29,50 @@ class Password(str):
 T = TypeVar('T', str, int, float, dt.date, dt.datetime, Path, dict, list, Password)
 
 
+def extract_optional_type(t: Any):
+    if get_origin(t) is Union:
+        types = tuple(x for x in get_args(t) if x is not type(None))
+        return Union[types] # type: ignore
+    return t
+
+
 def convert_to_type(data_type: Any, value: str,
                     *,
                     case_sensitive: bool = True):
     """
     Converts `value` to `data_type`, if not possible raises the appropriate error
     """
+    _data_type = extract_optional_type(data_type)
 
-    if data_type is Any or data_type is bool:
+    if _data_type is Any or _data_type is bool:
         return value
-    elif data_type is str or data_type is Password:
+    elif _data_type is str or _data_type is Password:
         return str(value)
-    elif data_type is int:
+    elif _data_type is int:
         return int(value)
-    elif data_type is float:
+    elif _data_type is float:
         return float(value)
-    elif data_type is UUID:
+    elif _data_type is UUID:
         return UUID(value)
-    elif data_type is dt.date:
+    elif _data_type is dt.date:
         return dt.date.fromisoformat(value)
-    elif data_type is dt.datetime:
+    elif _data_type is dt.datetime:
         return dt.datetime.fromisoformat(value)
-    elif data_type is Path:
+    elif _data_type is Path:
         p = Path(value)
         if not p.exists():
             raise FileNotFoundError(f'File not found: "{value}"')
         return p
-    elif data_type is dict:
+    elif _data_type is dict:
         return json.loads(value)
-    elif get_origin(data_type) is Literal:
-        possible_fields = get_args(data_type)
+    elif inspect.isclass(_data_type) and issubclass(_data_type, Enum):
+        return _data_type[value].value
+    elif _data_type is list or get_origin(_data_type) is list:
+        list_type = get_args(_data_type)
+        return [convert_to_type(list_type[0] if list_type else str,
+                                x) for x in value.split(' ')]
+    elif get_origin(_data_type) is Literal:
+        possible_fields = get_args(_data_type)
         _possible_fields_case = possible_fields
         if not case_sensitive:
             _possible_fields_case = [x.lower() for x in possible_fields] + [
@@ -67,12 +81,10 @@ def convert_to_type(data_type: Any, value: str,
             possible_fields = ', '.join(possible_fields)
             raise ValueError(f'"{value}" is not a valid value for Literal[{possible_fields}]')
         return value
-    elif data_type is list or get_origin(data_type) is list:
-        list_type = get_args(data_type)
+    elif _data_type is list or get_origin(_data_type) is list:
+        list_type = get_args(_data_type)
         return [convert_to_type(list_type[0] if list_type else str,
                                 x) for x in value.split(' ')]
-    elif issubclass(data_type, Enum):
-        return data_type[value].value
     else:
         raise NotImplementedError(f'No parser implemented for data type "{data_type}"')
 
diff --git a/pyproject.toml b/pyproject.toml
index d1c19fd..7e303bd 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "piou"
-version = "0.10.0"
+version = "0.10.1"
 description = "A CLI toolkit"
 authors = ["Julien Brayere <julien.brayere@gmail.com>"]
 license = "MIT"
diff --git a/tests/test_cli.py b/tests/test_cli.py
index 9c9766b..cf59203 100644
--- a/tests/test_cli.py
+++ b/tests/test_cli.py
@@ -3,7 +3,7 @@
 import re
 from enum import Enum
 from pathlib import Path
-from typing import Literal
+from typing import Literal, Optional
 from uuid import UUID
 
 import pytest
@@ -35,10 +35,24 @@ def test_command_option(cmd, is_required, is_positional):
     assert cmd.is_positional_arg == is_positional
 
 
+@pytest.mark.parametrize('data_type, expected', [
+    (str, str),
+    (Optional[str], str),
+    (list, list),
+    (list[str], list[str]),
+    (Optional[list[int]], list[int]),
+    ])
+def test_extract_optional_type(data_type, expected):
+    from piou.utils import extract_optional_type
+
+    assert extract_optional_type(data_type) == expected
+
+
 @pytest.mark.parametrize('data_type, value, expected', [
     (str, '123', '123'),
     (str, 'foo bar', 'foo bar'),
     (int, '123', 123),
+    (int, '123', 123),
     (float, '123', 123),
     (float, '0.123', 0.123),
     # (bytes, 'foo'.encode('utf-8'), b'foo'),
@@ -56,6 +70,7 @@ def test_command_option(cmd, is_required, is_positional):
 def test_convert_to_type(data_type, value, expected):
     from piou.utils import convert_to_type
     assert convert_to_type(data_type, value) == expected
+    assert convert_to_type(Optional[data_type], value) == expected
 
 
 def testing_case_sensitivity():