diff --git a/OpenRA.Mods.RA/Air/HeliReturn.cs b/OpenRA.Mods.RA/Air/HeliReturn.cs
index 69722e2f96..f799f78c0f 100755
--- a/OpenRA.Mods.RA/Air/HeliReturn.cs
+++ b/OpenRA.Mods.RA/Air/HeliReturn.cs
@@ -40,7 +40,7 @@ namespace OpenRA.Mods.RA.Air
 
 			var res = dest.TraitOrDefault<Reservable>();
 			if (res != null)
-				self.Trait<Helicopter>().reservation = res.Reserve(self);
+				self.Trait<Helicopter>().reservation = res.Reserve(dest, self);
 
 			var exit = dest.Info.Traits.WithInterface<ExitInfo>().FirstOrDefault();
 			var offset = exit != null ? exit.SpawnOffset : int2.Zero;
diff --git a/OpenRA.Mods.RA/Air/Helicopter.cs b/OpenRA.Mods.RA/Air/Helicopter.cs
index 44885b3f31..481ed30bd0 100755
--- a/OpenRA.Mods.RA/Air/Helicopter.cs
+++ b/OpenRA.Mods.RA/Air/Helicopter.cs
@@ -92,7 +92,7 @@ namespace OpenRA.Mods.RA.Air
 				if (Reservable.IsReserved(order.TargetActor)) return;
 				var res = order.TargetActor.TraitOrDefault<Reservable>();
 				if (res != null)
-					reservation = res.Reserve(self);
+					reservation = res.Reserve(order.TargetActor, self);
 
 				var exit = order.TargetActor.Info.Traits.WithInterface<ExitInfo>().FirstOrDefault();
 				var offset = exit != null ? exit.SpawnOffset : int2.Zero;
diff --git a/OpenRA.Mods.RA/Air/Plane.cs b/OpenRA.Mods.RA/Air/Plane.cs
index 21c3b780d8..4c785871d9 100755
--- a/OpenRA.Mods.RA/Air/Plane.cs
+++ b/OpenRA.Mods.RA/Air/Plane.cs
@@ -41,11 +41,12 @@ namespace OpenRA.Mods.RA.Air
 				if (self.Trait<IMove>().Altitude == 0)
 				{	
 					/* not spawning in the air, so try to assoc. with our afld. this is a hack. */
-					var res = self.World.FindUnits(self.CenterLocation, self.CenterLocation)
-						.Select( a => a.TraitOrDefault<Reservable>() ).FirstOrDefault( a => a != null );
+					var afld = self.World.FindUnits(self.CenterLocation, self.CenterLocation)
+						.FirstOrDefault( a => a.HasTrait<Reservable>() );
+					var res = afld.Trait<Reservable>();
 
 					if (res != null)
-						reservation = res.Reserve(self);
+						reservation = res.Reserve(afld, self);
 				}
 			}
 		}
diff --git a/OpenRA.Mods.RA/Air/ReturnToBase.cs b/OpenRA.Mods.RA/Air/ReturnToBase.cs
index 50319ac224..5a7ae48ce5 100755
--- a/OpenRA.Mods.RA/Air/ReturnToBase.cs
+++ b/OpenRA.Mods.RA/Air/ReturnToBase.cs
@@ -43,7 +43,7 @@ namespace OpenRA.Mods.RA.Air
 			if (res != null)
 			{
 				plane.UnReserve();
-				plane.reservation = res.Reserve(self);
+				plane.reservation = res.Reserve(dest, self);
 			}
 
 			var landPos = dest.CenterLocation;
diff --git a/OpenRA.Mods.RA/Reservable.cs b/OpenRA.Mods.RA/Reservable.cs
index f32e37eae8..2a750f9df8 100755
--- a/OpenRA.Mods.RA/Reservable.cs
+++ b/OpenRA.Mods.RA/Reservable.cs
@@ -28,13 +28,14 @@ namespace OpenRA.Mods.RA
 				reservedFor = null;		/* not likely to arrive now. */
 		}
 
-		public IDisposable Reserve(Actor forActor)
+		public IDisposable Reserve(Actor self, Actor forActor)
 		{
 			reservedFor = forActor;
 
-			return new DisposableAction(() => { reservedFor = null; },
+			return new DisposableAction(() => reservedFor = null,
 										() => Game.RunAfterTick(() => 
-			                        {throw new InvalidOperationException("Attempted to finalize an undisposed DisposableAction");})
+			                            {throw new InvalidOperationException("Attempted to finalize an undisposed DisposableAction. {0} ({1}) reserved {2} ({3})"
+			                                                            .F(forActor.Info.Name, forActor.ActorID, self.Info.Name, self.ActorID));})
 			);
 		}