diff --git a/OpenRA.Game/Map/Map.cs b/OpenRA.Game/Map/Map.cs
index 4287087ffb..c757ebf841 100644
--- a/OpenRA.Game/Map/Map.cs
+++ b/OpenRA.Game/Map/Map.cs
@@ -1020,33 +1020,6 @@ namespace OpenRA
 			ProjectedCells = new ProjectedCellRegion(this, tl, br).ToArray();
 		}
 
-		public void FixOpenAreas()
-		{
-			var r = new Random();
-			var tileset = Rules.TileSet;
-
-			for (var j = Bounds.Top; j < Bounds.Bottom; j++)
-			{
-				for (var i = Bounds.Left; i < Bounds.Right; i++)
-				{
-					var type = Tiles[new MPos(i, j)].Type;
-					var index = Tiles[new MPos(i, j)].Index;
-					if (!tileset.Templates.ContainsKey(type))
-					{
-						Console.WriteLine("Unknown Tile ID {0}".F(type));
-						continue;
-					}
-
-					var template = tileset.Templates[type];
-					if (!template.PickAny)
-						continue;
-
-					index = (byte)r.Next(0, template.TilesCount);
-					Tiles[new MPos(i, j)] = new TerrainTile(type, index);
-				}
-			}
-		}
-
 		public byte GetTerrainIndex(CPos cell)
 		{
 			const short InvalidCachedTerrainIndex = -1;
diff --git a/OpenRA.Game/Map/TileSet.cs b/OpenRA.Game/Map/TileSet.cs
index a6189def17..6b4afbba9c 100644
--- a/OpenRA.Game/Map/TileSet.cs
+++ b/OpenRA.Game/Map/TileSet.cs
@@ -14,6 +14,7 @@ using System.IO;
 using System.Linq;
 using OpenRA.FileSystem;
 using OpenRA.Primitives;
+using OpenRA.Support;
 using OpenRA.Traits;
 
 namespace OpenRA
@@ -34,6 +35,11 @@ namespace OpenRA
 		float MaxHeightColorBrightness { get; }
 	}
 
+	public interface ITerrainInfoNotifyMapCreated : ITerrainInfo
+	{
+		void MapCreated(Map map);
+	}
+
 	public class TerrainTileInfo
 	{
 		[FieldLoader.Ignore]
@@ -140,7 +146,7 @@ namespace OpenRA
 		}
 	}
 
-	public class TileSet : ITerrainInfo
+	public class TileSet : ITerrainInfo, ITerrainInfoNotifyMapCreated
 	{
 		public const string TerrainPaletteInternalName = "terrain";
 
@@ -270,5 +276,22 @@ namespace OpenRA
 		float ITerrainInfo.MinHeightColorBrightness { get { return MinHeightColorBrightness; } }
 		float ITerrainInfo.MaxHeightColorBrightness { get { return MaxHeightColorBrightness; } }
 		TerrainTile ITerrainInfo.DefaultTerrainTile { get { return new TerrainTile(Templates.First().Key, 0); } }
+
+		void ITerrainInfoNotifyMapCreated.MapCreated(Map map)
+		{
+			// Randomize PickAny tile variants
+			var r = new MersenneTwister();
+			for (var j = map.Bounds.Top; j < map.Bounds.Bottom; j++)
+			{
+				for (var i = map.Bounds.Left; i < map.Bounds.Right; i++)
+				{
+					var type = map.Tiles[new MPos(i, j)].Type;
+					if (!Templates.TryGetValue(type, out var template) || !template.PickAny)
+						continue;
+
+					map.Tiles[new MPos(i, j)] = new TerrainTile(type, (byte)r.Next(0, template.TilesCount));
+				}
+			}
+		}
 	}
 }
diff --git a/OpenRA.Mods.Common/UtilityCommands/ImportLegacyMapCommand.cs b/OpenRA.Mods.Common/UtilityCommands/ImportLegacyMapCommand.cs
index a7c6cd3e7e..56ea987367 100644
--- a/OpenRA.Mods.Common/UtilityCommands/ImportLegacyMapCommand.cs
+++ b/OpenRA.Mods.Common/UtilityCommands/ImportLegacyMapCommand.cs
@@ -99,7 +99,8 @@ namespace OpenRA.Mods.Common.UtilityCommands
 				Map.PlayerDefinitions = MapPlayers.ToMiniYaml();
 			}
 
-			Map.FixOpenAreas();
+			if (Map.Rules.TerrainInfo is ITerrainInfoNotifyMapCreated notifyMapCreated)
+				notifyMapCreated.MapCreated(Map);
 
 			var dest = Path.GetFileNameWithoutExtension(args[1]) + ".oramap";
 
diff --git a/OpenRA.Mods.Common/Widgets/Logic/Editor/NewMapLogic.cs b/OpenRA.Mods.Common/Widgets/Logic/Editor/NewMapLogic.cs
index 3d196df2a5..70e9174360 100644
--- a/OpenRA.Mods.Common/Widgets/Logic/Editor/NewMapLogic.cs
+++ b/OpenRA.Mods.Common/Widgets/Logic/Editor/NewMapLogic.cs
@@ -62,7 +62,9 @@ namespace OpenRA.Mods.Common.Widgets.Logic
 				map.SetBounds(tl, br);
 
 				map.PlayerDefinitions = new MapPlayers(map.Rules, 0).ToMiniYaml();
-				map.FixOpenAreas();
+
+				if (map.Rules.TerrainInfo is ITerrainInfoNotifyMapCreated notifyMapCreated)
+					notifyMapCreated.MapCreated(map);
 
 				Action<string> afterSave = uid =>
 				{