diff --git a/websocket-sharp/Net/ChunkStream.cs b/websocket-sharp/Net/ChunkStream.cs
index c1f574b1..91064485 100644
--- a/websocket-sharp/Net/ChunkStream.cs
+++ b/websocket-sharp/Net/ChunkStream.cs
@@ -321,7 +321,10 @@ namespace WebSocketSharp.Net
         _sawCr = false;
       }
 
-      if (_state == InputChunkState.Trailer && offset < length) {
+      if (_state == InputChunkState.Trailer) {
+        if (offset >= length)
+          return;
+
         _state = setTrailer (buffer, ref offset, length);
 
         if (_state == InputChunkState.Trailer)