diff --git a/homeassistant/components/telegram_bot/__init__.py b/homeassistant/components/telegram_bot/__init__.py
index f37a84a83a64..fed9021a46e4 100644
--- a/homeassistant/components/telegram_bot/__init__.py
+++ b/homeassistant/components/telegram_bot/__init__.py
@@ -702,7 +702,7 @@ class TelegramNotificationService:
                 }
                 if message_tag is not None:
                     event_data[ATTR_MESSAGE_TAG] = message_tag
-                if kwargs_msg[ATTR_MESSAGE_THREAD_ID] is not None:
+                if kwargs_msg.get(ATTR_MESSAGE_THREAD_ID) is not None:
                     event_data[ATTR_MESSAGE_THREAD_ID] = kwargs_msg[
                         ATTR_MESSAGE_THREAD_ID
                     ]