diff --git a/dust-lang/src/lexer.rs b/dust-lang/src/lexer.rs
index 7853f8f..6a170ae 100644
--- a/dust-lang/src/lexer.rs
+++ b/dust-lang/src/lexer.rs
@@ -354,7 +354,10 @@ impl<'src> Lexer<'src> {
     fn lex_minus(&mut self) -> Result<(Token<'src>, Span), LexError> {
         let start_position = self.position;
 
-        if self.peek_char().is_some_and(|char| char.is_ascii_digit()) {
+        if self
+            .peek_second_char()
+            .is_some_and(|char| char.is_ascii_digit())
+        {
             return self.lex_numeric();
         }