diff --git a/websocket-sharp/WebSocketFrame.cs b/websocket-sharp/WebSocketFrame.cs
index abd9cbef..827b8ae6 100644
--- a/websocket-sharp/WebSocketFrame.cs
+++ b/websocket-sharp/WebSocketFrame.cs
@@ -688,12 +688,6 @@ Extended Payload Length: {7}
       return frame;
     }
 
-    internal static void ReadFrameAsync (
-      Stream stream, Action<WebSocketFrame> completed, Action<Exception> error)
-    {
-      ReadFrameAsync (stream, true, completed, error);
-    }
-
     internal static void ReadFrameAsync (
       Stream stream, bool unmask, Action<WebSocketFrame> completed, Action<Exception> error)
     {