diff --git a/src/ast_values.hpp b/src/ast_values.hpp
index 9ec8389..c1d8f63 100644
--- a/src/ast_values.hpp
+++ b/src/ast_values.hpp
@@ -50,6 +50,7 @@
 
 enum class SpecialValue {
     List,
+    LeafList,
     Container,
     PresenceContainer
 };