A value of type 'int' cannot be used as a default parameter because there are no standards conversions to type C#

"A value of type 'int' cannot be used as a default parameter because there are no standards conversions to type 'Reality.Game.Rooms.RoomActorType'" is there error I'm getting within my C#.exe. The line(s) of error: ``` public RoomActor GetActorByReferenceId(int ReferenceId, RoomActorType ReferenceType = 1) { lock (this.mActors) { foreach (RoomActor actor in this.mActors.Values) { if ((actor.Type == ReferenceType) && (actor.ReferenceId == ReferenceId)) /* line of error */ { return actor; } } } return null; } ``` Here's Reality>Game>Rooms>RoomActorType.cs: ``` namespace Reality.Game.Rooms { using System; public enum RoomActorType { AiBot = 2, UserCharacter = 1, } } ``` Thanks!