diff --git a/websocket-sharp/Net/ChunkStream.cs b/websocket-sharp/Net/ChunkStream.cs
index 0339e2a1..c1f574b1 100644
--- a/websocket-sharp/Net/ChunkStream.cs
+++ b/websocket-sharp/Net/ChunkStream.cs
@@ -309,7 +309,10 @@ namespace WebSocketSharp.Net
           return;
       }
 
-      if (_state == InputChunkState.DataEnded && offset < length) {
+      if (_state == InputChunkState.DataEnded) {
+        if (offset >= length)
+          return;
+
         _state = seekCrLf (buffer, ref offset, length);
 
         if (_state == InputChunkState.DataEnded)