diff --git a/OpenRA.Mods.Common/EditorBrushes/EditorCopyPasteBrush.cs b/OpenRA.Mods.Common/EditorBrushes/EditorCopyPasteBrush.cs
index c0e0a0b4c0..1c5bc12052 100644
--- a/OpenRA.Mods.Common/EditorBrushes/EditorCopyPasteBrush.cs
+++ b/OpenRA.Mods.Common/EditorBrushes/EditorCopyPasteBrush.cs
@@ -165,7 +165,7 @@ namespace OpenRA.Mods.Common.Widgets
 				tiles.Add(cell, new ClipboardTile(mapTiles[cell], mapResources[cell], resourceLayerContents, mapHeight[cell]));
 
 				if (copyFilters.HasFlag(MapCopyFilters.Actors))
-					foreach (var preview in selection.SelectMany(editorActorLayer.PreviewsAt).Distinct())
+					foreach (var preview in selection.CellCoords.SelectMany(editorActorLayer.PreviewsAt).Distinct())
 						previews.TryAdd(preview.ID, preview);
 			}
 
@@ -182,6 +182,15 @@ namespace OpenRA.Mods.Common.Widgets
 			var sourcePos = clipboard.CellRegion.TopLeft;
 			var pasteVec = new CVec(pastePosition.X - sourcePos.X, pastePosition.Y - sourcePos.Y);
 
+			if (copyFilters.HasFlag(MapCopyFilters.Actors))
+			{
+				// Clear any existing actors in the paste cells.
+				var selectionSize = clipboard.CellRegion.BottomRight - clipboard.CellRegion.TopLeft;
+				var pasteRegion = new CellRegion(map.Grid.Type, pastePosition, pastePosition + selectionSize);
+				foreach (var regionActor in pasteRegion.CellCoords.SelectMany(editorActorLayer.PreviewsAt).ToHashSet())
+					editorActorLayer.Remove(regionActor);
+			}
+
 			foreach (var tileKeyValuePair in clipboard.Tiles)
 			{
 				var position = tileKeyValuePair.Key + pasteVec;
@@ -209,12 +218,6 @@ namespace OpenRA.Mods.Common.Widgets
 
 			if (copyFilters.HasFlag(MapCopyFilters.Actors))
 			{
-				// Clear any existing actors in the paste cells.
-				var selectionSize = clipboard.CellRegion.BottomRight - clipboard.CellRegion.TopLeft;
-				var pasteRegion = new CellRegion(map.Grid.Type, pastePosition, pastePosition + selectionSize);
-				foreach (var regionActor in pasteRegion.SelectMany(editorActorLayer.PreviewsAt).ToHashSet())
-					editorActorLayer.Remove(regionActor);
-
 				// Now place actors.
 				foreach (var actorKeyValuePair in clipboard.Actors)
 				{
@@ -238,6 +241,13 @@ namespace OpenRA.Mods.Common.Widgets
 
 		public void Undo()
 		{
+			if (copyFilters.HasFlag(MapCopyFilters.Actors))
+			{
+				// Clear existing actors.
+				foreach (var regionActor in undoClipboard.CellRegion.CellCoords.SelectMany(editorActorLayer.PreviewsAt).Distinct().ToList())
+					editorActorLayer.Remove(regionActor);
+			}
+
 			foreach (var tileKeyValuePair in undoClipboard.Tiles)
 			{
 				var position = tileKeyValuePair.Key;
@@ -262,10 +272,6 @@ namespace OpenRA.Mods.Common.Widgets
 
 			if (copyFilters.HasFlag(MapCopyFilters.Actors))
 			{
-				// Clear existing actors.
-				foreach (var regionActor in undoClipboard.CellRegion.SelectMany(editorActorLayer.PreviewsAt).Distinct().ToList())
-					editorActorLayer.Remove(regionActor);
-
 				// Place actors back again.
 				foreach (var actor in undoClipboard.Actors.Values)
 					editorActorLayer.Add(actor);
diff --git a/OpenRA.Mods.Common/Traits/World/EditorResourceLayer.cs b/OpenRA.Mods.Common/Traits/World/EditorResourceLayer.cs
index b0b4d063c4..c327d1660d 100644
--- a/OpenRA.Mods.Common/Traits/World/EditorResourceLayer.cs
+++ b/OpenRA.Mods.Common/Traits/World/EditorResourceLayer.cs
@@ -185,7 +185,7 @@ namespace OpenRA.Mods.Common.Traits
 		public int CalculateRegionValue(CellRegion sourceRegion)
 		{
 			var resourceValueInRegion = 0;
-			foreach (var cell in sourceRegion)
+			foreach (var cell in sourceRegion.CellCoords)
 			{
 				var mcell = cell.ToMPos(Map);
 				if (Map.Resources.Contains(mcell) && Map.Resources[mcell].Type != 0)
diff --git a/OpenRA.Mods.Common/Widgets/Logic/Editor/MapEditorSelectionLogic.cs b/OpenRA.Mods.Common/Widgets/Logic/Editor/MapEditorSelectionLogic.cs
index 12b77d3897..2d7432201b 100644
--- a/OpenRA.Mods.Common/Widgets/Logic/Editor/MapEditorSelectionLogic.cs
+++ b/OpenRA.Mods.Common/Widgets/Logic/Editor/MapEditorSelectionLogic.cs
@@ -123,7 +123,7 @@ namespace OpenRA.Mods.Common.Widgets.Logic
 				tiles.Add(cell, new ClipboardTile(mapTiles[cell], mapResources[cell], resourceLayer?.GetResource(cell), mapHeight[cell]));
 
 				if (copyFilters.HasFlag(MapCopyFilters.Actors))
-					foreach (var preview in selection.SelectMany(editorActorLayer.PreviewsAt).Distinct())
+					foreach (var preview in selection.CellCoords.SelectMany(editorActorLayer.PreviewsAt).Distinct())
 						previews.TryAdd(preview.ID, preview);
 			}