diff --git a/osu.Game/Online/Multiplayer/MultiplayerRoomSettings.cs b/osu.Game/Online/Multiplayer/MultiplayerRoomSettings.cs
index a25c332b47..d0e19d9f37 100644
--- a/osu.Game/Online/Multiplayer/MultiplayerRoomSettings.cs
+++ b/osu.Game/Online/Multiplayer/MultiplayerRoomSettings.cs
@@ -33,6 +33,7 @@ namespace osu.Game.Online.Multiplayer
         public IEnumerable<APIMod> Mods { get; set; } = Enumerable.Empty<APIMod>();
 
         [NotNull]
+        [Key(5)]
         public IEnumerable<APIMod> AllowedMods { get; set; } = Enumerable.Empty<APIMod>();
 
         public bool Equals(MultiplayerRoomSettings other)