diff --git a/aiogram/__init__.py b/aiogram/__init__.py
index e12ba3d9..169eed5f 100644
--- a/aiogram/__init__.py
+++ b/aiogram/__init__.py
@@ -38,5 +38,5 @@ __all__ = [
     'utils'
 ]
 
-__version__ = '2.6'
+__version__ = '2.6.1'
 __api_version__ = '4.6'
diff --git a/aiogram/types/__init__.py b/aiogram/types/__init__.py
index e4e27e1a..35461bb9 100644
--- a/aiogram/types/__init__.py
+++ b/aiogram/types/__init__.py
@@ -45,7 +45,7 @@ from .passport_element_error import PassportElementError, PassportElementErrorDa
     PassportElementErrorSelfie
 from .passport_file import PassportFile
 from .photo_size import PhotoSize
-from .poll import PollOption, Poll, PollAnswer
+from .poll import PollOption, Poll, PollAnswer, PollType
 from .pre_checkout_query import PreCheckoutQuery
 from .reply_keyboard import KeyboardButton, ReplyKeyboardMarkup, ReplyKeyboardRemove, KeyboardButtonPollType
 from .response_parameters import ResponseParameters
@@ -150,6 +150,7 @@ __all__ = (
     'Poll',
     'PollAnswer',
     'PollOption',
+    'PollType',
     'PreCheckoutQuery',
     'ReplyKeyboardMarkup',
     'ReplyKeyboardRemove',
diff --git a/aiogram/types/base.py b/aiogram/types/base.py
index 2fd9129d..e64d3398 100644
--- a/aiogram/types/base.py
+++ b/aiogram/types/base.py
@@ -120,7 +120,7 @@ class TelegramObject(ContextInstanceMixin, metaclass=MetaTelegramObject):
         return getattr(self, ALIASES_ATTR_NAME, {})
 
     @property
-    def values(self) -> typing.Tuple[str]:
+    def values(self) -> typing.Dict[str, typing.Any]:
         """
         Get values
 
@@ -161,9 +161,10 @@ class TelegramObject(ContextInstanceMixin, metaclass=MetaTelegramObject):
 
         :return:
         """
-        self.clean()
         result = {}
         for name, value in self.values.items():
+            if value is None:
+                continue
             if name in self.props:
                 value = self.props[name].export(self)
             if isinstance(value, TelegramObject):
@@ -191,7 +192,7 @@ class TelegramObject(ContextInstanceMixin, metaclass=MetaTelegramObject):
         return json.dumps(self.to_python())
 
     @classmethod
-    def create(cls: Type[T], *args: typing.Any, **kwargs: typing.Any) -> T:
+    def create(cls: typing.Type[T], *args: typing.Any, **kwargs: typing.Any) -> T:
         raise NotImplemented
 
     def __str__(self) -> str:
@@ -225,15 +226,15 @@ class TelegramObject(ContextInstanceMixin, metaclass=MetaTelegramObject):
             return self.props[key].set_value(self, value, self.conf.get('parent', None))
         raise KeyError(key)
 
-    def __contains__(self, item: typing.Dict[str, typing.Any]) -> bool:
+    def __contains__(self, item: str) -> bool:
         """
         Check key contains in that object
 
         :param item:
         :return:
         """
-        self.clean()
-        return item in self.values
+        # self.clean()
+        return bool(self.values.get(item, None))
 
     def __iter__(self) -> typing.Iterator[str]:
         """
@@ -263,7 +264,7 @@ class TelegramObject(ContextInstanceMixin, metaclass=MetaTelegramObject):
             yield value
 
     def __hash__(self) -> int:
-        def _hash(obj)-> int:
+        def _hash(obj) -> int:
             buf: int = 0
             if isinstance(obj, list):
                 for item in obj:
diff --git a/aiogram/types/input_media.py b/aiogram/types/input_media.py
index 95ca75ae..952e7a55 100644
--- a/aiogram/types/input_media.py
+++ b/aiogram/types/input_media.py
@@ -349,7 +349,7 @@ class MediaGroup(base.TelegramObject):
 
         :return:
         """
-        self.clean()
+        # self.clean()
         result = []
         for obj in self.media:
             if isinstance(obj, base.TelegramObject):
diff --git a/aiogram/types/poll.py b/aiogram/types/poll.py
index e5a485d4..86b41d7e 100644
--- a/aiogram/types/poll.py
+++ b/aiogram/types/poll.py
@@ -1,7 +1,7 @@
 import typing
 
-from . import base
-from . import fields
+from ..utils import helper
+from . import base, fields
 from .user import User
 
 
@@ -11,6 +11,7 @@ class PollOption(base.TelegramObject):
 
     https://core.telegram.org/bots/api#polloption
     """
+
     text: base.String = fields.Field()
     voter_count: base.Integer = fields.Field()
 
@@ -21,6 +22,7 @@ class PollAnswer(base.TelegramObject):
     
     https://core.telegram.org/bots/api#pollanswer
     """
+
     poll_id: base.String = fields.Field()
     user: User = fields.Field(base=User)
     option_ids: typing.List[base.Integer] = fields.ListField()
@@ -32,6 +34,7 @@ class Poll(base.TelegramObject):
     
     https://core.telegram.org/bots/api#poll
     """
+
     id: base.String = fields.Field()
     question: base.String = fields.Field()
     options: typing.List[PollOption] = fields.ListField(base=PollOption)
@@ -41,3 +44,10 @@ class Poll(base.TelegramObject):
     type: base.String = fields.Field()
     allows_multiple_answers: base.Boolean = fields.Field()
     correct_option_id: base.Integer = fields.Field()
+
+
+class PollType(helper.Helper):
+    mode = helper.HelperMode.snake_case
+
+    REGULAR = helper.Item()
+    QUIZ = helper.Item()
diff --git a/aiogram/types/reply_keyboard.py b/aiogram/types/reply_keyboard.py
index 59804f08..ced20417 100644
--- a/aiogram/types/reply_keyboard.py
+++ b/aiogram/types/reply_keyboard.py
@@ -12,7 +12,7 @@ class KeyboardButtonPollType(base.TelegramObject):
     """
     type: base.String = fields.Field()
 
-    def __init__(self, type: base.String):
+    def __init__(self, type: typing.Optional[base.String] = None):
         super(KeyboardButtonPollType, self).__init__(type=type)
 
 
@@ -110,10 +110,12 @@ class KeyboardButton(base.TelegramObject):
 
     def __init__(self, text: base.String,
                  request_contact: base.Boolean = None,
-                 request_location: base.Boolean = None):
+                 request_location: base.Boolean = None,
+                 request_poll: KeyboardButtonPollType = None):
         super(KeyboardButton, self).__init__(text=text,
                                              request_contact=request_contact,
-                                             request_location=request_location)
+                                             request_location=request_location,
+                                             request_poll=request_poll)
 
 
 class ReplyKeyboardRemove(base.TelegramObject):