diff --git a/ablescript/src/parser.rs b/ablescript/src/parser.rs
index 52a8577..59a8581 100644
--- a/ablescript/src/parser.rs
+++ b/ablescript/src/parser.rs
@@ -120,11 +120,10 @@ impl<'source> Parser<'source> {
     }
 
     /// Require next item to be equal with expected one
-    fn require(&mut self, expected: Token) -> Result<(), Error> {
-        match self.lexer.next() {
-            Some(t) if t == expected => Ok(()),
-            Some(t) => Err(Error::new(ErrorKind::UnexpectedToken(t), self.lexer.span())),
-            None => Err(Error::unexpected_eof(self.lexer.span().start)),
+    fn require(&mut self, required: Token) -> Result<(), Error> {
+        match self.checked_next()? {
+            t if t == required => Ok(()),
+            t => Err(Error::new(ErrorKind::UnexpectedToken(t), self.lexer.span())),
         }
     }
 
@@ -176,7 +175,7 @@ impl<'source> Parser<'source> {
                 })),
                 start..self.lexer.span().end,
             )),
-            
+
             Token::LeftBracket => match buf.take() {
                 Some(buf) => Ok(Expr::new(
                     self.index_flow(buf)?,