diff --git a/matrix_appservice_kakaotalk/kt/types/attachment/__init__.py b/matrix_appservice_kakaotalk/kt/types/attachment/__init__.py
index 9854339..0b590cb 100644
--- a/matrix_appservice_kakaotalk/kt/types/attachment/__init__.py
+++ b/matrix_appservice_kakaotalk/kt/types/attachment/__init__.py
@@ -13,6 +13,8 @@
 #
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
+from typing import Optional
+
 from attr import dataclass
 
 from mautrix.types import SerializableAttrs
@@ -23,9 +25,9 @@ from .mention import MentionStruct
 
 @dataclass(kw_only=True)
 class Attachment(SerializableAttrs):
-    shout: bool | None = None
-    mentions: list[MentionStruct] | None = None
-    urls: list[str] | None = None
+    shout: Optional[bool] = None
+    mentions: Optional[list[MentionStruct]] = None
+    urls: Optional[list[str]] = None
 
 
 @dataclass
diff --git a/matrix_appservice_kakaotalk/kt/types/channel/channel_info.py b/matrix_appservice_kakaotalk/kt/types/channel/channel_info.py
index e54eabd..afceae0 100644
--- a/matrix_appservice_kakaotalk/kt/types/channel/channel_info.py
+++ b/matrix_appservice_kakaotalk/kt/types/channel/channel_info.py
@@ -13,7 +13,7 @@
 #
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
-from typing import Generic, TypeVar
+from typing import Generic, TypeVar, Optional
 
 from attr import dataclass
 
@@ -48,7 +48,7 @@ class ChannelInfo(Channel):
     newChatCountInvalid: bool
     lastChatLogId: Long
     lastSeenLogId: Long
-    lastChatLog: Chatlog | None = None
+    lastChatLog: Optional[Chatlog] = None
     metaMap: ChannelMetaMap
     displayUserList: list[DisplayUserInfo]
     pushAlert: bool
diff --git a/matrix_appservice_kakaotalk/kt/types/openlink/open_channel_info.py b/matrix_appservice_kakaotalk/kt/types/openlink/open_channel_info.py
index 425a097..3bd3bde 100644
--- a/matrix_appservice_kakaotalk/kt/types/openlink/open_channel_info.py
+++ b/matrix_appservice_kakaotalk/kt/types/openlink/open_channel_info.py
@@ -13,6 +13,8 @@
 #
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
+from typing import Optional
+
 from attr import dataclass
 
 from mautrix.types import JSON
@@ -25,7 +27,7 @@ from . import OpenTokenComponent, OpenLink
 @dataclass(kw_only=True)
 class OpenChannelInfo(ChannelInfo, OpenChannel, OpenTokenComponent):
     directChannel: bool
-    openLink: OpenLink | None = None
+    openLink: Optional[OpenLink] = None
 
 
 @dataclass
diff --git a/matrix_appservice_kakaotalk/kt/types/user/channel_user.py b/matrix_appservice_kakaotalk/kt/types/user/channel_user.py
index 914e2ac..5b268ce 100644
--- a/matrix_appservice_kakaotalk/kt/types/user/channel_user.py
+++ b/matrix_appservice_kakaotalk/kt/types/user/channel_user.py
@@ -13,6 +13,8 @@
 #
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
+from typing import Optional
+
 from attr import dataclass
 
 from mautrix.types import SerializableAttrs
@@ -28,7 +30,7 @@ class ChannelUser(SerializableAttrs):
 @dataclass(kw_only=True)
 class PartialOpenLinkComponent(SerializableAttrs):
     """Substitute for Partial<OpenLinkComponent>"""
-    linkId: Long | None = None
+    linkId: Optional[Long] = None
 
 
 @dataclass