diff --git a/generate/lex.go b/generate/lex.go
index a20c3d9..c815aad 100644
--- a/generate/lex.go
+++ b/generate/lex.go
@@ -10,6 +10,7 @@ const (
 	TokenMethod parse.TokenKind = iota
 	TokenKey
 	TokenIdent
+	TokenOption
 	TokenComma
 	TokenLBrace
 	TokenRBrace
@@ -22,6 +23,7 @@ var tokenNames = map[parse.TokenKind] string {
 	TokenMethod:   "Method",
 	TokenKey:      "Key",
 	TokenIdent:    "Ident",
+	TokenOption:   "Option",
 	TokenComma:    "Comma",
 	TokenLBrace:   "LBrace",
 	TokenRBrace:   "RBrace",
@@ -122,6 +124,11 @@ func (this *lexer) nextInternal() (token parse.Token, err error) {
 			if this.eof { err = nil; return }
 			if err != nil { return }
 		}
+	// Option
+	case this.rune == '?':
+		token.Kind = TokenOption
+		appendRune()
+		if this.eof { err = nil; return }
 	// Comma
 	case this.rune == ',':
 		token.Kind = TokenComma
diff --git a/generate/lex_test.go b/generate/lex_test.go
index 8715cea..37676cf 100644
--- a/generate/lex_test.go
+++ b/generate/lex_test.go
@@ -16,6 +16,7 @@ func TestLex(test *testing.T) {
 		// wow
 		0001 Users []User,
 		0002 Followers U32,
+		0003 Wings ?Int,
 	}`))
 	if err != nil { test.Fatal(parse.Format(err)) }
 
@@ -42,6 +43,11 @@ func TestLex(test *testing.T) {
 		tok(TokenIdent,    "Followers"),
 		tok(TokenIdent,    "U32"),
 		tok(TokenComma,    ","),
+		tok(TokenKey,      "0003"),
+		tok(TokenIdent,    "Wings"),
+		tok(TokenOption,   "?"),
+		tok(TokenIdent,    "Int"),
+		tok(TokenComma,    ","),
 		tok(TokenRBrace,   "}"),
 		tok(parse.EOF,     ""),
 	}