diff --git a/osu.Game/Online/Multiplayer/MatchUserRequest.cs b/osu.Game/Online/Multiplayer/MatchUserRequest.cs
index 15c3ad0776..8c6809e7f3 100644
--- a/osu.Game/Online/Multiplayer/MatchUserRequest.cs
+++ b/osu.Game/Online/Multiplayer/MatchUserRequest.cs
@@ -3,6 +3,7 @@
 
 using System;
 using MessagePack;
+using osu.Game.Online.Multiplayer.MatchTypes.TeamVersus;
 
 namespace osu.Game.Online.Multiplayer
 {
@@ -11,6 +12,7 @@ namespace osu.Game.Online.Multiplayer
     /// </summary>
     [Serializable]
     [MessagePackObject]
+    [Union(0, typeof(ChangeTeamRequest))] // IMPORTANT: Add rules to SignalRUnionWorkaroundResolver for new derived types.
     public abstract class MatchUserRequest
     {
     }