diff --git a/OpenRA.Mods.RA/Buildings/BuildingInfluence.cs b/OpenRA.Mods.RA/Buildings/BuildingInfluence.cs
index be31f43dd2..1f2c4a423c 100755
--- a/OpenRA.Mods.RA/Buildings/BuildingInfluence.cs
+++ b/OpenRA.Mods.RA/Buildings/BuildingInfluence.cs
@@ -1,6 +1,6 @@
 #region Copyright & License Information
 /*
- * Copyright 2007-2011 The OpenRA Developers (see AUTHORS)
+ * Copyright 2007-2014 The OpenRA Developers (see AUTHORS)
  * This file is part of OpenRA, which is free software. It is made
  * available to you under the terms of the GNU General Public License
  * as published by the Free Software Foundation. For more information,
@@ -14,7 +14,7 @@ namespace OpenRA.Mods.RA.Buildings
 {
 	public class BuildingInfluenceInfo : ITraitInfo
 	{
-		public object Create( ActorInitializer init ) { return new BuildingInfluence( init.world ); }
+		public object Create(ActorInitializer init) { return new BuildingInfluence(init.world); }
 	}
 
 	public class BuildingInfluence
@@ -22,30 +22,39 @@ namespace OpenRA.Mods.RA.Buildings
 		Actor[,] influence;
 		Map map;
 
-		public BuildingInfluence( World world )
+		public BuildingInfluence(World world)
 		{
 			map = world.Map;
 
 			influence = new Actor[map.MapSize.X, map.MapSize.Y];
 
-			world.ActorAdded +=
-				a => { if (a.HasTrait<Building>())
-					ChangeInfluence(a, a.Trait<Building>(), true); };
-			world.ActorRemoved +=
-				a => { if (a.HasTrait<Building>())
-					ChangeInfluence(a, a.Trait<Building>(), false); };
+			world.ActorAdded +=	a =>
+			{
+				var b = a.TraitOrDefault<Building>();
+				if (b != null)
+					ChangeInfluence(a, b, true);
+			};
+
+			world.ActorRemoved += a =>
+			{
+				var b = a.TraitOrDefault<Building>();
+				if (b != null)
+					ChangeInfluence(a, b, false);
+			};
 		}
 
-		void ChangeInfluence( Actor a, Building building, bool isAdd )
+		void ChangeInfluence(Actor a, Building building, bool isAdd)
 		{
-			foreach( var u in FootprintUtils.Tiles( a.Info.Name, a.Info.Traits.Get<BuildingInfo>(), a.Location ) )
-				if( map.IsInMap( u ) )
-					influence[ u.X, u.Y ] = isAdd ? a : null;
+			foreach (var u in FootprintUtils.Tiles(a.Info.Name, building.Info, a.Location))
+				if (map.IsInMap(u))
+					influence[u.X, u.Y] = isAdd ? a : null;
 		}
 
 		public Actor GetBuildingAt(CPos cell)
 		{
-			if (!map.IsInMap(cell)) return null;
+			if (!map.IsInMap(cell))
+				return null;
+
 			return influence[cell.X, cell.Y];
 		}
 	}