diff --git a/ziffers/mapper.py b/ziffers/mapper.py
index 2fa7149..4f60175 100644
--- a/ziffers/mapper.py
+++ b/ziffers/mapper.py
@@ -1,5 +1,6 @@
 from lark import Transformer
 from .classes import (
+    Ziffers,
     Whitespace,
     DurationChange,
     OctaveChange,