diff --git a/docs/diagram.md b/docs/diagram.md
index 40dd651..8a018ef 100644
--- a/docs/diagram.md
+++ b/docs/diagram.md
@@ -76,5 +76,6 @@ class letheql_engine {
 
 class letheql_evaluator {
     Eval()
+    eval()
 }
 ```