diff --git a/YHProto/protocol.go b/YHProto/protocol.go
index d4db439..0dbac00 100644
--- a/YHProto/protocol.go
+++ b/YHProto/protocol.go
@@ -204,8 +204,7 @@ func (codec *EchoPackage) DecodeWsMessage(msg wsutil.Message) (err error) {
 		return ErrTooLargePackage
 	}
 
-	msgLen := echoPkgHeaderLen + int(codec.H.Len)
-	if len(msg.Payload)-echoPkgHeaderLen < msgLen {
+	if len(msg.Payload)-echoPkgHeaderLen < int(codec.H.Len) {
 		return ErrNotEnoughStream
 	}