diff --git a/OpenRa.Game/PlaceBuilding.cs b/OpenRa.Game/PlaceBuilding.cs
index 653627a841..5f4b8835d1 100644
--- a/OpenRa.Game/PlaceBuilding.cs
+++ b/OpenRa.Game/PlaceBuilding.cs
@@ -1,45 +1,50 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using OpenRa.Game.GameRules;
-
-namespace OpenRa.Game
-{
-	class PlaceBuilding : IOrderGenerator
-	{
-		public readonly Player Owner;
-		public readonly string Name;
-
-		public PlaceBuilding(Player owner, string name)
-		{
-			Owner = owner;
-			Name = name;
-		}
-
-		public IEnumerable<Order> Order(int2 xy, bool lmb)
-		{
-			if( lmb )
-			{
-				var bi = (UnitInfo.BuildingInfo)Rules.UnitInfo[ Name ];
-				if( Footprint.Tiles( bi, xy ).Any(
-					t => !Game.IsCellBuildable( t,
-						bi.WaterBound ? UnitMovementType.Float : UnitMovementType.Wheel ) ) )
-					yield break;
-
-				var maxDistance = bi.Adjacent + 2;	/* real-ra is weird. this is 1 GAP. */
-				if( !Footprint.Tiles( bi, xy ).Any(
-					t => Game.GetDistanceToBase( t, Owner ) < maxDistance ) )
-					yield break;
-
-				yield return OpenRa.Game.Order.PlaceBuilding( Owner, xy, Name );
-			}
-			else // rmb
-			{
-				Game.world.AddFrameEndTask( _ => { Game.controller.orderGenerator = null; } );
-			}
-		}
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using OpenRa.Game.GameRules;
 
-		public void Tick() { }
-	}
-}
+namespace OpenRa.Game
+{
+	class PlaceBuilding : IOrderGenerator
+	{
+		public readonly Player Owner;
+		public readonly string Name;
+
+		public PlaceBuilding(Player owner, string name)
+		{
+			Owner = owner;
+			Name = name;
+		}
+
+		public IEnumerable<Order> Order(int2 xy, bool lmb)
+		{
+			if( lmb )
+			{
+				var bi = (UnitInfo.BuildingInfo)Rules.UnitInfo[ Name ];
+				if( Footprint.Tiles( bi, xy ).Any(
+					t => !Game.IsCellBuildable( t,
+						bi.WaterBound ? UnitMovementType.Float : UnitMovementType.Wheel ) ) )
+					yield break;
+
+				var maxDistance = bi.Adjacent + 2;	/* real-ra is weird. this is 1 GAP. */
+				if( !Footprint.Tiles( bi, xy ).Any(
+					t => Game.GetDistanceToBase( t, Owner ) < maxDistance ) )
+					yield break;
+
+				yield return OpenRa.Game.Order.PlaceBuilding( Owner, xy, Name );
+			}
+			else // rmb
+			{
+				Game.world.AddFrameEndTask( _ => { Game.controller.orderGenerator = null; } );
+			}
+		}
+
+		public void Tick()
+		{
+			var producing = Owner.Producing( "Building" );
+			if( producing == null || producing.Item != Name || producing.RemainingTime != 0 )
+				Game.world.AddFrameEndTask( _ => { Game.controller.orderGenerator = null; } );
+		}
+	}
+}
diff --git a/OpenRa.Game/UnitOrders.cs b/OpenRa.Game/UnitOrders.cs
index 41f0070599..fab96e2bc7 100755
--- a/OpenRa.Game/UnitOrders.cs
+++ b/OpenRa.Game/UnitOrders.cs
@@ -69,13 +69,14 @@ namespace OpenRa.Game
 					Game.world.AddFrameEndTask( _ =>
 					{
 						var building = Rules.UnitInfo[ order.TargetString ];
+						var producing = order.Player.Producing( "Building" );
+						if( producing == null || producing.Item != order.TargetString || producing.RemainingTime != 0 )
+							return;
+
 						Log.Write( "Player \"{0}\" builds {1}", order.Player.PlayerName, building.Name );
 
-						//Adjust placement for cursor to be in middle
 						Game.world.Add( new Actor( building.Name, order.TargetLocation - GameRules.Footprint.AdjustForBuildingSize( building.Name ), order.Player ) );
 
-						Game.controller.orderGenerator = null;
-
 						order.Player.FinishProduction(Rules.UnitCategory[building.Name]);
 					} );
 					break;