diff --git a/src/lex/mod.rs b/src/lex/mod.rs
index f67adb1..2650ccf 100644
--- a/src/lex/mod.rs
+++ b/src/lex/mod.rs
@@ -117,8 +117,8 @@ impl Lexer {
     }
 
     pub fn prev(&mut self) -> Option<&Token> {
-        let prev = self.history.last()?;
         self.offset += 1;
+        let prev = &self.history[self.history.len() - self.offset];
         Some(prev)
     }