diff --git a/OpenRA.Game/Activities/Activity.cs b/OpenRA.Game/Activities/Activity.cs
index 45fbf91f38..18a188d6e2 100644
--- a/OpenRA.Game/Activities/Activity.cs
+++ b/OpenRA.Game/Activities/Activity.cs
@@ -152,7 +152,6 @@ namespace OpenRA.Activities
 			set { NextActivity = value; }
 		}
 
-		public bool IsIdle { get; protected set; }
 		public bool IsInterruptible { get; protected set; }
 		public bool IsCanceled { get { return State == ActivityState.Canceled; } }
 
diff --git a/OpenRA.Game/Actor.cs b/OpenRA.Game/Actor.cs
index 148385fe1f..1192346848 100644
--- a/OpenRA.Game/Actor.cs
+++ b/OpenRA.Game/Actor.cs
@@ -53,7 +53,7 @@ namespace OpenRA
 		public IOccupySpace OccupiesSpace { get; private set; }
 		public ITargetable[] Targetables { get; private set; }
 
-		public bool IsIdle { get { return CurrentActivity == null || CurrentActivity.IsIdle; } }
+		public bool IsIdle { get { return CurrentActivity == null; } }
 		public bool IsDead { get { return Disposed || (health != null && health.IsDead); } }
 
 		public CPos Location { get { return OccupiesSpace.TopLeft; } }
diff --git a/OpenRA.Mods.Common/Activities/Air/FlyCircle.cs b/OpenRA.Mods.Common/Activities/Air/FlyCircle.cs
index 875f5c4555..dbf9197d7b 100644
--- a/OpenRA.Mods.Common/Activities/Air/FlyCircle.cs
+++ b/OpenRA.Mods.Common/Activities/Air/FlyCircle.cs
@@ -21,7 +21,6 @@ namespace OpenRA.Mods.Common.Activities
 
 		public FlyCircle(Actor self)
 		{
-			IsIdle = true;
 			plane = self.Trait<Aircraft>();
 			cruiseAltitude = plane.Info.CruiseAltitude;
 		}
diff --git a/OpenRA.Mods.Common/Activities/Air/HeliFlyCircle.cs b/OpenRA.Mods.Common/Activities/Air/HeliFlyCircle.cs
index 78a0be5688..68db365be7 100644
--- a/OpenRA.Mods.Common/Activities/Air/HeliFlyCircle.cs
+++ b/OpenRA.Mods.Common/Activities/Air/HeliFlyCircle.cs
@@ -22,7 +22,6 @@ namespace OpenRA.Mods.Common.Activities
 		public HeliFlyCircle(Actor self)
 		{
 			helicopter = self.Trait<Aircraft>();
-			IsIdle = true;
 		}
 
 		public override Activity Tick(Actor self)