diff --git a/generate/protocol.go b/generate/protocol.go
index a733f1b..6ebd99c 100644
--- a/generate/protocol.go
+++ b/generate/protocol.go
@@ -95,9 +95,10 @@ func (typ TypeTableDefined) String() string {
 }
 
 type Field struct {
-	Name string
-	Doc  string
-	Type Type
+	Name   string
+	Doc    string
+	Type   Type
+	Option bool
 }
 
 func (field Field) String() string {