diff --git a/README.md b/README.md
index 9b72599..52c6efa 100644
--- a/README.md
+++ b/README.md
@@ -115,6 +115,7 @@ that.  Really you need to run (GNU) make in the `docs/notebooks` and
     |   |               type inference
     |   |               work-in-progress compiler
     |   |
+    |   |-- Elm - interpreter
     |   |-- Nim - interpreter
     |   |-- Ocaml - work-in-progress interpreter
     |   `-- Python - interpreter