diff --git a/rust/src/scanner.rs b/rust/src/scanner.rs
index 25dc98c..dcbd3ac 100644
--- a/rust/src/scanner.rs
+++ b/rust/src/scanner.rs
@@ -158,8 +158,8 @@ impl<'a> Iterator for Scanner<'a> {
         Some(match self.advance() {
             c if is_alpha(c) => self.identifier(),
             c if c.is_ascii_digit() => self.number(),
-            // '(' => Token::new(self, TokenKind::LeftParen),
-            '(' => self.make_token(TokenKind::LeftParen),
+            '(' => Token::new(self, TokenKind::LeftParen),
+            // '(' => self.make_token(TokenKind::LeftParen),
         //     ')' => self.make_token(TokenKind::RightParen),
         //     '{' => self.make_token(TokenKind::LeftBrace),
         //     '}' => self.make_token(TokenKind::RightBrace),
@@ -211,7 +211,7 @@ pub struct Token<'a> {
 }
 
 impl<'a> Token<'a> {
-    fn new(scanner: &'a Scanner, kind: TokenKind) -> Self {
+    fn new(scanner: &Scanner<'a>, kind: TokenKind) -> Self {
         Token {
             kind,
             value: std::str::from_utf8(&scanner.source[..scanner.current]).unwrap(),