diff --git a/OpenRa.Game/Game.cs b/OpenRa.Game/Game.cs
index e10c64f540..5a96292f88 100644
--- a/OpenRa.Game/Game.cs
+++ b/OpenRa.Game/Game.cs
@@ -165,7 +165,7 @@ namespace OpenRa.Game
 					if (--oreTicks == 0)
 					{
 						var oresw = new Stopwatch();
-						map.GrowOre(p => IsCellBuildable(p, UnitMovementType.Wheel), SharedRandom);
+						map.GrowOre(SharedRandom);
 						OreTime = oresw.ElapsedTime();
 						oreTicks = oreFrequency;
 					}
diff --git a/OpenRa.Game/Graphics/WorldRenderer.cs b/OpenRa.Game/Graphics/WorldRenderer.cs
index b9d36453f8..c018f79f98 100644
--- a/OpenRa.Game/Graphics/WorldRenderer.cs
+++ b/OpenRa.Game/Graphics/WorldRenderer.cs
@@ -99,7 +99,7 @@ namespace OpenRa.Game.Graphics
             
             lineRenderer.Flush();
 
-			renderer.DrawText(string.Format("RenderFrame {0} ({2:F1} ms) Tick {1} ({3:F1} ms) Ore ({4:F1} ms)", 
+			renderer.DrawText(string.Format("RenderFrame {0} ({2:F1} ms)\nTick {1} ({3:F1} ms)\nOre ({4:F1} ms)", 
 				Game.RenderFrame, Game.orderManager.FrameNumber,
 				Game.RenderTime * 1000, 
 				Game.TickTime * 1000,
diff --git a/OpenRa.Game/Ore.cs b/OpenRa.Game/Ore.cs
index 1bcc61df07..90005f01e9 100644
--- a/OpenRa.Game/Ore.cs
+++ b/OpenRa.Game/Ore.cs
@@ -10,8 +10,17 @@ namespace OpenRa.Game
 	{
 		/* todo: deal with ore pits */
 
-		public static void GrowOre(this Map map, 
-			Func<int2, bool> canSpreadIntoCell, Random r)
+		static bool CanSpreadInto(int i, int j)
+		{
+			if (Game.BuildingInfluence.GetBuildingAt(new int2(i, j)) != null)
+				return false;
+
+			return TerrainCosts.Cost(UnitMovementType.Wheel,
+				Game.worldRenderer.terrainRenderer.tileSet.GetWalkability(Game.map.MapTiles[i, j]))
+				< double.PositiveInfinity;
+		}
+
+		public static void GrowOre(this Map map, Random r)
 		{
 			var mini = map.XOffset; var maxi = map.XOffset + map.Width;
 			var minj = map.YOffset; var maxj = map.YOffset + map.Height;
@@ -28,7 +37,7 @@ namespace OpenRa.Game
 						if (!map.HasOverlay(i, j)
 							&& r.NextDouble() < chance
 							&& map.GetOreDensity(i, j) > 0
-							&& canSpreadIntoCell(new int2(i, j)))
+							&& CanSpreadInto(i,j))
 							newOverlay[i, j] = ChooseOre();
 					}