diff --git a/aiogram/bot/bot.py b/aiogram/bot/bot.py
index 384e9221..41f30af1 100644
--- a/aiogram/bot/bot.py
+++ b/aiogram/bot/bot.py
@@ -872,8 +872,7 @@ class Bot(BaseBot, DataMixin, ContextInstanceMixin):
                         correct_option_id: typing.Optional[base.Integer] = None,
                         explanation: typing.Optional[base.String] = None,
                         explanation_parse_mode: typing.Optional[base.String] = None,
-                        open_period: typing.Union[
-                            base.Integer, datetime.datetime, datetime.timedelta, None] = None,
+                        open_period: typing.Union[base.Integer, None] = None,
                         close_date: typing.Union[
                             base.Integer, datetime.datetime, datetime.timedelta, None] = None,
                         is_closed: typing.Optional[base.Boolean] = None,
@@ -908,7 +907,7 @@ class Bot(BaseBot, DataMixin, ContextInstanceMixin):
         :param explanation_parse_mode: Mode for parsing entities in the explanation. See formatting options for more details.
         :type explanation_parse_mode: :obj:`typing.Optional[base.String]`
         :param open_period: Amount of time in seconds the poll will be active after creation, 5-600. Can't be used together with close_date.
-        :type open_period: :obj:`typing.Union[base.Integer, datetime.datetime, datetime.timedelta, None]`
+        :type open_period: :obj:`typing.Union[base.Integer, None]`
         :param close_date: Point in time (Unix timestamp) when the poll will be automatically closed. Must be at least 5 and no more than 600 seconds in the future. Can't be used together with open_period.
         :type close_date: :obj:`typing.Union[base.Integer, datetime.datetime, datetime.timedelta, None]`
         :param is_closed: Pass True, if the poll needs to be immediately closed
diff --git a/aiogram/types/poll.py b/aiogram/types/poll.py
index 9e1315ca..a709edcd 100644
--- a/aiogram/types/poll.py
+++ b/aiogram/types/poll.py
@@ -1,9 +1,10 @@
+import datetime
 import typing
 
-from ..utils import helper
 from . import base, fields
 from .message_entity import MessageEntity
 from .user import User
+from ..utils import helper
 from ..utils.text_decorations import html_decoration, markdown_decoration
 
 
@@ -48,6 +49,8 @@ class Poll(base.TelegramObject):
     correct_option_id: base.Integer = fields.Field()
     explanation: base.String = fields.Field()
     explanation_entities: base.String = fields.ListField(base=MessageEntity)
+    open_period: base.Integer = fields.Field()
+    close_date: datetime.datetime = fields.DateTimeField()
 
     def parse_entities(self, as_html=True):
         text_decorator = html_decoration if as_html else markdown_decoration