diff --git a/OpenRA.Game/Traits/TraitsInterfaces.cs b/OpenRA.Game/Traits/TraitsInterfaces.cs
index 2327aa94f5..3d6ed857d1 100644
--- a/OpenRA.Game/Traits/TraitsInterfaces.cs
+++ b/OpenRA.Game/Traits/TraitsInterfaces.cs
@@ -270,6 +270,7 @@ namespace OpenRA.Traits
 		WDist LargestActorRadius { get; }
 		WDist LargestBlockingActorRadius { get; }
 
+		void UpdateOccupiedCells(IOccupySpace ios);
 		event Action<CPos> CellUpdated;
 	}
 
diff --git a/OpenRA.Mods.Common/Traits/Crushable.cs b/OpenRA.Mods.Common/Traits/Crushable.cs
index 2c8efda2b1..0ef095a91b 100644
--- a/OpenRA.Mods.Common/Traits/Crushable.cs
+++ b/OpenRA.Mods.Common/Traits/Crushable.cs
@@ -90,12 +90,12 @@ namespace OpenRA.Mods.Common.Traits
 
 		protected override void TraitEnabled(Actor self)
 		{
-			self.World.ActorMap.UpdatePosition(self, self.OccupiesSpace);
+			self.World.ActorMap.UpdateOccupiedCells(self.OccupiesSpace);
 		}
 
 		protected override void TraitDisabled(Actor self)
 		{
-			self.World.ActorMap.UpdatePosition(self, self.OccupiesSpace);
+			self.World.ActorMap.UpdateOccupiedCells(self.OccupiesSpace);
 		}
 	}
 }
diff --git a/OpenRA.Mods.Common/Traits/Mobile.cs b/OpenRA.Mods.Common/Traits/Mobile.cs
index a16ec3556d..8b583fe4cb 100644
--- a/OpenRA.Mods.Common/Traits/Mobile.cs
+++ b/OpenRA.Mods.Common/Traits/Mobile.cs
@@ -159,8 +159,11 @@ namespace OpenRA.Mods.Common.Traits
 				var oldValue = movementTypes;
 				movementTypes = value;
 				if (value != oldValue)
+				{
+					self.World.ActorMap.UpdateOccupiedCells(self.OccupiesSpace);
 					foreach (var n in notifyMoving)
 						n.MovementTypeChanged(self, value);
+				}
 			}
 		}
 		#endregion
diff --git a/OpenRA.Mods.Common/Traits/World/ActorMap.cs b/OpenRA.Mods.Common/Traits/World/ActorMap.cs
index 3a6f01783d..1e400bb39d 100644
--- a/OpenRA.Mods.Common/Traits/World/ActorMap.cs
+++ b/OpenRA.Mods.Common/Traits/World/ActorMap.cs
@@ -410,6 +410,15 @@ namespace OpenRA.Mods.Common.Traits
 				influenceNode = influenceNode.Next;
 		}
 
+		public void UpdateOccupiedCells(IOccupySpace ios)
+		{
+			if (CellUpdated == null)
+				return;
+
+			foreach (var c in ios.OccupiedCells())
+				CellUpdated(c.First);
+		}
+
 		void ITick.Tick(Actor self)
 		{
 			// Position updates are done in one pass