diff --git a/OpenRA.Game/Map/Map.cs b/OpenRA.Game/Map/Map.cs
index 82c1407d6e..e9bd0fc47a 100644
--- a/OpenRA.Game/Map/Map.cs
+++ b/OpenRA.Game/Map/Map.cs
@@ -429,7 +429,7 @@ namespace OpenRA
 			{
 				var uv = cell.ToMPos(Grid.Type);
 				cellProjection[uv] = new PPos[0];
-				inverseCellProjection[uv] = new List<MPos>();
+				inverseCellProjection[uv] = new List<MPos>(1);
 			}
 
 			// Initialize projections