diff --git a/OpenRa.Game/GameRules/TechTree.cs b/OpenRa.Game/GameRules/TechTree.cs
index afcd0fc728..2ed7f9882a 100755
--- a/OpenRa.Game/GameRules/TechTree.cs
+++ b/OpenRa.Game/GameRules/TechTree.cs
@@ -23,7 +23,7 @@ namespace OpenRa.Game.GameRules
 		public Cache<string, List<Actor>> GatherBuildings( Player player )
 		{
 			var ret = new Cache<string, List<Actor>>( x => new List<Actor>() );
-			foreach( var b in Game.world.Actors.Where( x => x.Owner == player && Rules.UnitCategory[ x.unitInfo.Name ] == "Building" ) )
+			foreach( var b in Game.world.Actors.Where( x => x.Owner == player && x.unitInfo is UnitInfo.BuildingInfo ) )
 				ret[ b.unitInfo.Name ].Add( b );
 			return ret;
 		}
diff --git a/OpenRa.Game/PlaceBuilding.cs b/OpenRa.Game/PlaceBuilding.cs
index 2848aaf783..ff9803ac3e 100644
--- a/OpenRa.Game/PlaceBuilding.cs
+++ b/OpenRa.Game/PlaceBuilding.cs
@@ -39,7 +39,7 @@ namespace OpenRa.Game
 
 		public void Tick()
 		{
-			var producing = Owner.Producing( "Building" );
+			var producing = Owner.Producing( Rules.UnitCategory[ Building.Name ] );
 			if( producing == null || producing.Item != Building.Name || producing.RemainingTime != 0 )
 				Game.world.AddFrameEndTask( _ => { Game.controller.orderGenerator = null; } );
 		}
diff --git a/OpenRa.Game/UnitOrders.cs b/OpenRa.Game/UnitOrders.cs
index 6486e4aa57..9c478f137b 100755
--- a/OpenRa.Game/UnitOrders.cs
+++ b/OpenRa.Game/UnitOrders.cs
@@ -79,7 +79,7 @@ namespace OpenRa.Game
 					Game.world.AddFrameEndTask( _ =>
 					{
 						var building = (UnitInfo.BuildingInfo)Rules.UnitInfo[ order.TargetString ];
-						var producing = order.Player.Producing( "Building" );
+						var producing = order.Player.Producing(Rules.UnitCategory[order.TargetString]);
 						if( producing == null || producing.Item != order.TargetString || producing.RemainingTime != 0 )
 							return;
 
@@ -110,10 +110,10 @@ namespace OpenRa.Game
 							() => Game.world.AddFrameEndTask(
 								_ =>
 								{
+									var isBuilding = group == "Building" || group == "Defense";
 									if (order.Player == Game.LocalPlayer)
-										Game.PlaySound(group == "Building" 
-											? "conscmp1.aud" : "unitrdy1.aud", false);
-									if (group != "Building" && group != "Defense")
+										Game.PlaySound( isBuilding ? "conscmp1.aud" : "unitrdy1.aud", false);
+									if (!isBuilding)
 										Game.BuildUnit(order.Player, order.TargetString);
 								})));
 					break;
diff --git a/units.ini b/units.ini
index 06210f5211..160d40ec4b 100755
--- a/units.ini
+++ b/units.ini
@@ -155,6 +155,9 @@ FTUR
 GAP
 SAM
 MSLO
+; SBAG
+; BRIK
+; FENC
 
 
 [BuildingTypes]
@@ -175,9 +178,6 @@ BARR
 TENT
 KENN
 FIX
-; SBAG
-; BRIK
-; FENC
 FACF
 WEAF
 SYRF
@@ -262,7 +262,7 @@ Description=Construction Yard
 Traits=Building, RenderBuilding
 Dimensions=3,3
 Footprint=xxx xxx xxx
-Produces=Building
+Produces=Building,Defense
 [PROC]
 Description=Ore Refinery
 Traits=Building, RenderBuilding, AcceptsOre