diff --git a/OpenRA.Mods.Cnc/Traits/Buildings/ClonesProducedUnits.cs b/OpenRA.Mods.Cnc/Traits/Buildings/ClonesProducedUnits.cs
index 08fd3ebaee..c2566d9ca5 100644
--- a/OpenRA.Mods.Cnc/Traits/Buildings/ClonesProducedUnits.cs
+++ b/OpenRA.Mods.Cnc/Traits/Buildings/ClonesProducedUnits.cs
@@ -9,7 +9,6 @@
  */
 #endregion
 
-using System.Collections.Generic;
 using OpenRA.Mods.Common;
 using OpenRA.Mods.Common.Traits;
 using OpenRA.Primitives;
@@ -22,7 +21,7 @@ namespace OpenRA.Mods.Cnc.Traits
 	{
 		[FieldLoader.Require]
 		[Desc("Uses the \"Cloneable\" trait to determine whether or not we should clone a produced unit.")]
-		public readonly HashSet<string> CloneableTypes = new HashSet<string>();
+		public readonly BitSet<CloneableType> CloneableTypes = default(BitSet<CloneableType>);
 
 		public object Create(ActorInitializer init) { return new ClonesProducedUnits(init, this); }
 	}
diff --git a/OpenRA.Mods.Cnc/Traits/Cloneable.cs b/OpenRA.Mods.Cnc/Traits/Cloneable.cs
index b96d89558a..db51985756 100644
--- a/OpenRA.Mods.Cnc/Traits/Cloneable.cs
+++ b/OpenRA.Mods.Cnc/Traits/Cloneable.cs
@@ -10,16 +10,20 @@
 #endregion
 
 using System.Collections.Generic;
+using OpenRA.Primitives;
 using OpenRA.Traits;
 
 namespace OpenRA.Mods.Cnc.Traits
 {
+	// Type tag for CloneableTypes
+	public class CloneableType { }
+
 	[Desc("Actors with the \"ClonesProducedUnits\" trait will produce a free duplicate of me.")]
 	public class CloneableInfo : TraitInfo<Cloneable>
 	{
 		[FieldLoader.Require]
 		[Desc("This unit's cloneable type is:")]
-		public readonly HashSet<string> Types = new HashSet<string>();
+		public readonly BitSet<CloneableType> Types = default(BitSet<CloneableType>);
 	}
 
 	public class Cloneable { }