diff --git a/OpenRA.Game/Actor.cs b/OpenRA.Game/Actor.cs
index f64d091aea..6667199b97 100644
--- a/OpenRA.Game/Actor.cs
+++ b/OpenRA.Game/Actor.cs
@@ -48,6 +48,7 @@ namespace OpenRA
 		public Activity CurrentActivity { get; private set; }
 
 		public int Generation;
+		public Actor ReplacedByActor;
 
 		public IEffectiveOwner EffectiveOwner { get; private set; }
 		public IOccupySpace OccupiesSpace { get; private set; }
diff --git a/OpenRA.Mods.Common/Activities/Transform.cs b/OpenRA.Mods.Common/Activities/Transform.cs
index 3c8bc77187..03ab901344 100644
--- a/OpenRA.Mods.Common/Activities/Transform.cs
+++ b/OpenRA.Mods.Common/Activities/Transform.cs
@@ -132,6 +132,8 @@ namespace OpenRA.Mods.Common.Activities
 				foreach (var nt in self.TraitsImplementing<INotifyTransform>())
 					nt.AfterTransform(a);
 
+				self.ReplacedByActor = a;
+
 				if (selected)
 					w.Selection.Add(w, a);