diff --git a/src/scanner.zig b/src/scanner.zig
index a0a2ea2..c4c61e7 100644
--- a/src/scanner.zig
+++ b/src/scanner.zig
@@ -148,12 +148,13 @@ pub const Scanner = struct {
 
     fn peek(self: *Scanner) u8 {
         if (self.isAtEnd()) return 0;
-        return self.source[self.current];
+        if (self.current == 0) return 0;
+        return self.source[self.current - 1];
     }
 
     fn peekNext(self: *Scanner) u8 {
         if (self.current + 1 >= self.source.len) return 0;
-        return self.source[self.current + 1];
+        return self.source[self.current];
     }
 
     fn skipWhitespace(self: *Scanner) void {