diff --git a/OpenRA.Mods.RA/OpenRA.Mods.RA.csproj b/OpenRA.Mods.RA/OpenRA.Mods.RA.csproj
index 3d4967f001..57dba908c2 100644
--- a/OpenRA.Mods.RA/OpenRA.Mods.RA.csproj
+++ b/OpenRA.Mods.RA/OpenRA.Mods.RA.csproj
@@ -502,7 +502,6 @@
     <Compile Include="Scripting\Properties\TransportProperties.cs" />
     <Compile Include="Scripting\Global\CameraGlobal.cs" />
     <Compile Include="Scripting\Properties\ChronosphereProperties.cs" />
-    <Compile Include="Scripting\ScriptInvulnerable.cs" />
     <Compile Include="Console\ChatCommands.cs" />
     <Compile Include="Console\DevCommands.cs" />
     <Compile Include="Console\HelpCommand.cs" />
diff --git a/OpenRA.Mods.RA/Scripting/Properties/HealthProperties.cs b/OpenRA.Mods.RA/Scripting/Properties/HealthProperties.cs
index 445622cee2..c11867ff9e 100644
--- a/OpenRA.Mods.RA/Scripting/Properties/HealthProperties.cs
+++ b/OpenRA.Mods.RA/Scripting/Properties/HealthProperties.cs
@@ -33,22 +33,4 @@ namespace OpenRA.Mods.RA.Scripting
 		[Desc("Maximum health of the actor.")]
 		public int MaxHealth { get { return health.MaxHP; } }
 	}
-
-	[ScriptPropertyGroup("General")]
-	public class InvulnerableProperties : ScriptActorProperties, Requires<ScriptInvulnerableInfo>
-	{
-		ScriptInvulnerable invulnerable;
-		public InvulnerableProperties(ScriptContext context, Actor self)
-			: base(context, self)
-		{
-			invulnerable = self.Trait<ScriptInvulnerable>();
-		}
-
-		[Desc("Set or query unit invulnerablility.")]
-		public bool Invulnerable
-		{
-			get { return invulnerable.Invulnerable; }
-			set { invulnerable.Invulnerable = value; }
-		}
-	}
 }
\ No newline at end of file
diff --git a/OpenRA.Mods.RA/Scripting/ScriptInvulnerable.cs b/OpenRA.Mods.RA/Scripting/ScriptInvulnerable.cs
deleted file mode 100644
index f2c8e5f067..0000000000
--- a/OpenRA.Mods.RA/Scripting/ScriptInvulnerable.cs
+++ /dev/null
@@ -1,28 +0,0 @@
-#region Copyright & License Information
-/*
- * 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,
- * see COPYING.
- */
-#endregion
-
-using OpenRA.GameRules;
-using OpenRA.Traits;
-
-namespace OpenRA.Mods.RA
-{
-	[Desc("Allows map scripts to make this actor invulnerable via actor.Invulnerable = true.")]
-	class ScriptInvulnerableInfo : TraitInfo<ScriptInvulnerable> {}
-
-	class ScriptInvulnerable : IDamageModifier
-	{
-		public bool Invulnerable = false;
-
-		public int GetDamageModifier(Actor attacker, DamageWarhead warhead)
-		{
-			return Invulnerable ? 0 : 100;
-		}
-	}
-}
diff --git a/mods/ra/maps/desert-shellmap/desert-shellmap.lua b/mods/ra/maps/desert-shellmap/desert-shellmap.lua
index cc8b82f733..404ad46fc6 100644
--- a/mods/ra/maps/desert-shellmap/desert-shellmap.lua
+++ b/mods/ra/maps/desert-shellmap/desert-shellmap.lua
@@ -109,8 +109,8 @@ end
 
 SetupAlliedUnits = function()
 	Utils.Do(Map.NamedActors, function(a)
-		if a.Owner == allies and a.HasProperty("Invulnerable") then
-			a.Invulnerable = true
+		if a.Owner == allies and a.HasProperty("AcceptsUpgrade") and a.AcceptsUpgrade("unkillable") then
+			a.GrantUpgrade("unkillable")
 			a.Stance = "Defend"
 		end
 	end)
diff --git a/mods/ra/maps/desert-shellmap/map.yaml b/mods/ra/maps/desert-shellmap/map.yaml
index 9410038d01..711f967fa9 100644
--- a/mods/ra/maps/desert-shellmap/map.yaml
+++ b/mods/ra/maps/desert-shellmap/map.yaml
@@ -1295,19 +1295,20 @@ Rules:
 		Health:
 			HP: 200
 	^Vehicle:
-		ScriptInvulnerable:
 		GivesBounty:
 			Percentage: 0
 		GainsExperience:
 			Upgrades:
+		InvulnerabilityUpgrade@UNKILLABLE:
+			RequiresUpgrade: unkillable
 	^Tank:
-		ScriptInvulnerable:
 		GivesBounty:
 			Percentage: 0
 		GainsExperience:
 			Upgrades:
+		InvulnerabilityUpgrade@UNKILLABLE:
+			RequiresUpgrade: unkillable
 	^Infantry:
-		ScriptInvulnerable:
 		GivesBounty:
 			Percentage: 0
 		GainsExperience:
@@ -1318,20 +1319,25 @@ Rules:
 			VolumeMultiplier: 0.1
 		DeathSounds@ZAPPED:
 			VolumeMultiplier: 0.1
+		InvulnerabilityUpgrade@UNKILLABLE:
+			RequiresUpgrade: unkillable
 	^Ship:
-		ScriptInvulnerable:
 		GivesBounty:
 			Percentage: 0
 		GainsExperience:
 			Upgrades:
+		InvulnerabilityUpgrade@UNKILLABLE:
+			RequiresUpgrade: unkillable
 	^Plane:
-		ScriptInvulnerable:
 		GivesBounty:
 			Percentage: 0
+		InvulnerabilityUpgrade@UNKILLABLE:
+			RequiresUpgrade: unkillable
 	^Building:
-		ScriptInvulnerable:
 		GivesBounty:
 			Percentage: 0
+		InvulnerabilityUpgrade@UNKILLABLE:
+			RequiresUpgrade: unkillable
 
 Sequences:
 
diff --git a/mods/ra/maps/fort-lonestar/fort-lonestar.lua b/mods/ra/maps/fort-lonestar/fort-lonestar.lua
index d75e196207..a6f22481cb 100644
--- a/mods/ra/maps/fort-lonestar/fort-lonestar.lua
+++ b/mods/ra/maps/fort-lonestar/fort-lonestar.lua
@@ -147,7 +147,7 @@ WorldLoaded = function()
 
 	Utils.Do(Snipers, function(a)
 		if a.Owner == soviets then
-			a.Invulnerable = true
+			a.GrantUpgrade("unkillable")
 		end
 	end)
 
diff --git a/mods/ra/maps/fort-lonestar/map.yaml b/mods/ra/maps/fort-lonestar/map.yaml
index fdc907b7c1..d6130c546c 100644
--- a/mods/ra/maps/fort-lonestar/map.yaml
+++ b/mods/ra/maps/fort-lonestar/map.yaml
@@ -665,7 +665,8 @@ Rules:
 			HP: 200
 		AutoTarget:
 			InitialStance: Defend
-		ScriptInvulnerable:
+		InvulnerabilityUpgrade@UNKILLABLE:
+			RequiresUpgrade: unkillable
 	SPY:
 		Inherits: ^Infantry
 		Buildable: