diff --git a/OpenRA.Mods.Common/OpenRA.Mods.Common.csproj b/OpenRA.Mods.Common/OpenRA.Mods.Common.csproj
index 7ddbb3a6a0..d1ba89c909 100644
--- a/OpenRA.Mods.Common/OpenRA.Mods.Common.csproj
+++ b/OpenRA.Mods.Common/OpenRA.Mods.Common.csproj
@@ -199,6 +199,7 @@
     <Compile Include="Pathfinder\CellInfo.cs" />
     <Compile Include="PlayerExtensions.cs" />
     <Compile Include="Scripting\Global\FacingGlobal.cs" />
+    <Compile Include="Scripting\ScriptUpgradesCache.cs" />
     <Compile Include="Scripting\Global\HSLColorGlobal.cs" />
     <Compile Include="Scripting\Global\UserInterfaceGlobal.cs" />
     <Compile Include="ServerTraits\ColorValidator.cs" />
diff --git a/OpenRA.Mods.Common/Scripting/Properties/UpgradeProperties.cs b/OpenRA.Mods.Common/Scripting/Properties/UpgradeProperties.cs
index eba3b40e6e..c0d016b38b 100644
--- a/OpenRA.Mods.Common/Scripting/Properties/UpgradeProperties.cs
+++ b/OpenRA.Mods.Common/Scripting/Properties/UpgradeProperties.cs
@@ -8,6 +8,9 @@
  */
 #endregion
 
+using System;
+using System.IO;
+using System.Linq;
 using OpenRA.Mods.Common.Traits;
 using OpenRA.Scripting;
 using OpenRA.Traits;
@@ -17,35 +20,56 @@ namespace OpenRA.Mods.Common.Scripting
 	[ScriptPropertyGroup("General")]
 	public class UpgradeProperties : ScriptActorProperties, Requires<UpgradeManagerInfo>
 	{
-		UpgradeManager um;
+		readonly UpgradeManager um;
+		readonly ScriptUpgradesCache validUpgrades;
+
 		public UpgradeProperties(ScriptContext context, Actor self)
 			: base(context, self)
 		{
 			um = self.Trait<UpgradeManager>();
+			validUpgrades = self.World.WorldActor.TraitOrDefault<ScriptUpgradesCache>();
 		}
 
 		[Desc("Grant an upgrade to this actor.")]
 		public void GrantUpgrade(string upgrade)
 		{
-			um.GrantUpgrade(Self, upgrade, this);
+			if (validUpgrades == null)
+				throw new InvalidOperationException("Can not grant upgrades because there is no ScriptUpgradesCache defined!");
+
+			if (validUpgrades.Info.Upgrades.Contains(upgrade))
+				um.GrantUpgrade(Self, upgrade, this);
+			else
+				throw new InvalidDataException("The ScriptUpgradesCache does not contain a definition for upgrade `{0}`".F(upgrade));
 		}
 
 		[Desc("Revoke an upgrade that was previously granted using GrantUpgrade.")]
 		public void RevokeUpgrade(string upgrade)
 		{
-			um.RevokeUpgrade(Self, upgrade, this);
+			if (validUpgrades == null)
+				throw new InvalidOperationException("Can not grant upgrades because there is no ScriptUpgradesCache defined!");
+
+			if (validUpgrades.Info.Upgrades.Contains(upgrade))
+				um.RevokeUpgrade(Self, upgrade, this);
+			else
+				throw new InvalidDataException("The ScriptUpgradesCache does not contain a definition for upgrade `{0}`".F(upgrade));
 		}
 
 		[Desc("Grant a limited-time upgrade to this actor.")]
 		public void GrantTimedUpgrade(string upgrade, int duration)
 		{
-			um.GrantTimedUpgrade(Self, upgrade, duration);
+			if (validUpgrades == null)
+				throw new InvalidOperationException("Can not grant upgrades because there is no ScriptUpgradesCache defined!");
+
+			if (validUpgrades.Info.Upgrades.Contains(upgrade))
+				um.GrantTimedUpgrade(Self, upgrade, duration);
+			else
+				throw new InvalidDataException("The ScriptUpgradesCache does not contain a definition for upgrade `{0}`".F(upgrade));
 		}
 
 		[Desc("Check whether this actor accepts a specific upgrade.")]
 		public bool AcceptsUpgrade(string upgrade)
 		{
-			return um.AcceptsUpgrade(Self, upgrade);
+			return validUpgrades != null && validUpgrades.Info.Upgrades.Contains(upgrade) && um.AcceptsUpgrade(Self, upgrade);
 		}
 	}
 }
\ No newline at end of file
diff --git a/OpenRA.Mods.Common/Scripting/ScriptUpgradesCache.cs b/OpenRA.Mods.Common/Scripting/ScriptUpgradesCache.cs
new file mode 100644
index 0000000000..8ed69dfc0c
--- /dev/null
+++ b/OpenRA.Mods.Common/Scripting/ScriptUpgradesCache.cs
@@ -0,0 +1,33 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2015 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.Traits;
+
+namespace OpenRA.Mods.Common.Scripting
+{
+	[Desc("Allows granting upgrades to actors from Lua scripts.")]
+	public class ScriptUpgradesCacheInfo : ITraitInfo
+	{
+		[Desc("Upgrades that can be granted from the scripts.")]
+		public readonly string[] Upgrades = { };
+
+		public object Create(ActorInitializer init) { return new ScriptUpgradesCache(this); }
+	}
+
+	public sealed class ScriptUpgradesCache
+	{
+		public readonly ScriptUpgradesCacheInfo Info;
+
+		public ScriptUpgradesCache(ScriptUpgradesCacheInfo info)
+		{
+			Info = info;
+		}
+	}
+}
diff --git a/mods/ra/maps/desert-shellmap/map.yaml b/mods/ra/maps/desert-shellmap/map.yaml
index f1a3e27e83..04ffff3df0 100644
--- a/mods/ra/maps/desert-shellmap/map.yaml
+++ b/mods/ra/maps/desert-shellmap/map.yaml
@@ -1259,6 +1259,8 @@ Rules:
 			ValuePerUnit: 0
 		LuaScript:
 			Scripts: desert-shellmap.lua
+		ScriptUpgradesCache:
+			Upgrades: unkillable
 		-StartGameNotification:
 	^Vehicle:
 		GivesBounty:
diff --git a/mods/ra/maps/fort-lonestar/map.yaml b/mods/ra/maps/fort-lonestar/map.yaml
index 175e16a0ee..b05d28267f 100644
--- a/mods/ra/maps/fort-lonestar/map.yaml
+++ b/mods/ra/maps/fort-lonestar/map.yaml
@@ -488,6 +488,8 @@ Rules:
 		-MPStartLocations:
 		LuaScript:
 			Scripts: fort-lonestar.lua
+		ScriptUpgradesCache:
+			Upgrades: unkillable
 	FORTCRATE:
 		Inherits: ^Crate
 		SupportPowerCrateAction@parabombs: