diff --git a/uml/classdiagram.dot b/uml/classdiagram.dot
index 57e8877..82ab78a 100644
--- a/uml/classdiagram.dot
+++ b/uml/classdiagram.dot
@@ -83,7 +83,7 @@ digraph LodgeReservationSystem {
     Account -> AccountReservationList [arrowhead=diamond, label="contains"];
     Account -> Address [arrowhead=diamond, label="mailing_address"];
     Account -> EmailAddress [arrowhead=diamond, label="email_address"];
-    AccountList -> Account [arrowhead=diamond, label="contains"];
+    AccountList -> Account [arrowhead=odiamond, label="contains"];
     AccountReservationList -> IReservation [arrowhead=odiamond, label="contains 0..*"];
     Reservation -> Address [arrowhead=diamond, label="physical_address\nmailing_address"];
     Reservation -> KitchenTypeEnum [arrowhead=diamond, label="kitchen"];