diff --git a/src/Fleck/WebSocketConnection.cs b/src/Fleck/WebSocketConnection.cs
index 5aba274..318de65 100644
--- a/src/Fleck/WebSocketConnection.cs
+++ b/src/Fleck/WebSocketConnection.cs
@@ -223,8 +223,8 @@ private void CloseSocket()
       _closing = true;
       OnClose();
       _closed = true;
-      Socket.Close();
-      Socket.Dispose();
+      Socket?.Close();
+      Socket?.Dispose();
       _closing = false;
     }