diff --git a/telegram-application/src/core/tg_service/schemas.py b/telegram-application/src/core/tg_service/schemas.py
index 7395db9..5e0aae4 100644
--- a/telegram-application/src/core/tg_service/schemas.py
+++ b/telegram-application/src/core/tg_service/schemas.py
@@ -8,7 +8,7 @@ from src.core.common.schemas import BaseModelWithSerializeDatetime
 class MessageFromChatSchema(BaseModelWithSerializeDatetime):
     id: PositiveInt
     user_id: PositiveInt
-    chat_id: NegativeInt
+    chat_id: int
     text: str
     message_time: datetime
 
diff --git a/telegram-application/src/core/tg_service/utils.py b/telegram-application/src/core/tg_service/utils.py
index 610ddcd..c32396e 100644
--- a/telegram-application/src/core/tg_service/utils.py
+++ b/telegram-application/src/core/tg_service/utils.py
@@ -15,6 +15,9 @@ def check_message_condition(
         sender: User,
         chat_type: CustomChatTypes,
 ) -> bool:
+    if not sender:
+        return False
+
     if isinstance(sender, Channel):
         return False