diff --git a/part4/Main.elm b/part4/Main.elm
index 66b83f7..1317498 100644
--- a/part4/Main.elm
+++ b/part4/Main.elm
@@ -55,6 +55,8 @@ initialModel =
 
 
 {-| TODO add a type annotation to this value
+
+HINT: The type aliases above may come in handy here!
 -}
 elmHubHeader =
     header []