diff --git a/README.md b/README.md
index c263887..74ad7b0 100644
--- a/README.md
+++ b/README.md
@@ -277,6 +277,8 @@ frees its resources on garbage collection, like an implicit scope.
 
 ### TODO Serialization and Deserialization
 
+### TODO Unions
+
 ### TODO Data Model
 
 ## License