diff --git a/OpenRa.Game/GameRules/UnitInfo.cs b/OpenRa.Game/GameRules/UnitInfo.cs
index d4893ac17c..7da2ac2480 100755
--- a/OpenRa.Game/GameRules/UnitInfo.cs
+++ b/OpenRa.Game/GameRules/UnitInfo.cs
@@ -35,7 +35,7 @@ namespace OpenRa.Game.GameRules
 		public readonly bool Invisible = false;
 		public readonly string Owner = "allies,soviet"; // TODO: make this an enum
 		public readonly int Points = 0;
-		public readonly string Prerequisite = "";
+		public readonly string[] Prerequisite = new string[ 0 ];
 		public readonly string Primary = null;
 		public readonly string Secondary = null;
 		public readonly int ROT = 0;
diff --git a/OpenRa.Game/TechTree/Item.cs b/OpenRa.Game/TechTree/Item.cs
index cf09781cd7..a76fe37767 100755
--- a/OpenRa.Game/TechTree/Item.cs
+++ b/OpenRa.Game/TechTree/Item.cs
@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Linq;
 using OpenRa.FileFormats;
 using OpenRa.Game.GameRules;
 
@@ -38,11 +39,9 @@ namespace OpenRa.TechTree
 			return race;
 		}
 
-		static Tuple<string[],string[]> ParsePrerequisites(string prerequisites, string tag)
+		static Tuple<string[],string[]> ParsePrerequisites(string[] prerequisites, string tag)
 		{
-			List<string> allied = new List<string>(prerequisites.ToLowerInvariant().Split(
-				new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries));
-
+			List<string> allied = prerequisites.Select( x => x.ToLowerInvariant() ).ToList();
 			List<string> soviet = new List<string>(allied);
 
 			if (allied.Remove("stek"))