diff --git a/src/fsm.js b/src/fsm.js
index 0d382eb..f3a3b9a 100644
--- a/src/fsm.js
+++ b/src/fsm.js
@@ -31,6 +31,7 @@ export function openAutomaton(states, editable = false) {
     try {
       states = createStateList(graph);
       type();
+      createLetters();
     } catch (e) {
       console.error(e);
     }