diff --git a/conn/internal/conn.py b/conn/internal/conn.py
index 90ab6a8..34ab239 100644
--- a/conn/internal/conn.py
+++ b/conn/internal/conn.py
@@ -1,4 +1,4 @@
-from fastapi.websockets import WebSocket, WebSocketState
+from fastapi.websockets import WebSocket, WebSocketState, WebSocketDisconnect
 from websockets.exceptions import ConnectionClosed
 from message import Message
 from dataclasses import dataclass
@@ -23,11 +23,11 @@ async def receive(self):
         return Message.from_str(await self.conn.receive_text())
 
     async def send(self, msg: Message):
-        if self.conn.client_state == WebSocketState.DISCONNECTED:
+        if self.conn.application_state == WebSocketState.DISCONNECTED:
             return
 
         try:
             await self.conn.send_text(msg.to_str())
-        except ConnectionClosed:
+        except (ConnectionClosed, WebSocketDisconnect):
             # 커넥션이 종료되었는데도 타이밍 문제로 인해 커넥션을 가져왔을 수 있음.
             return
diff --git a/conn/test/fixtures.py b/conn/test/fixtures.py
index f0c2c3f..bc2e2f1 100644
--- a/conn/test/fixtures.py
+++ b/conn/test/fixtures.py
@@ -1,6 +1,6 @@
 from unittest.mock import MagicMock, AsyncMock
 
-from fastapi.websockets import WebSocket
+from fastapi.websockets import WebSocket, WebSocketState
 
 
 class ConnMock():
@@ -9,6 +9,7 @@ def __init__(self):
         self.receive_text = AsyncMock()
         self.send_text = AsyncMock()
         self.close = AsyncMock()
+        self.application_state = WebSocketState.CONNECTED
 
 
 def create_connection_mock() -> ConnMock: