diff --git a/OpenRA.Game/OpenRA.Game.csproj b/OpenRA.Game/OpenRA.Game.csproj
index bcfb422fe3..6e1e58beaa 100644
--- a/OpenRA.Game/OpenRA.Game.csproj
+++ b/OpenRA.Game/OpenRA.Game.csproj
@@ -244,6 +244,7 @@
+
diff --git a/OpenRA.Game/Primitives/ReadOnlyList.cs b/OpenRA.Game/Primitives/ReadOnlyList.cs
new file mode 100644
index 0000000000..38dcd13246
--- /dev/null
+++ b/OpenRA.Game/Primitives/ReadOnlyList.cs
@@ -0,0 +1,71 @@
+#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 System;
+using System.Collections.Generic;
+
+namespace OpenRA
+{
+ ///
+ /// A minimal read only list interface for .NET 4
+ ///
+ ///
+ /// .NET 4.5 has an implementation built-in, this code is not meant to
+ /// duplicate it but provide a compatible interface that can be replaced
+ /// when we switch to .NET 4.5 or higher.
+ ///
+ public interface IReadOnlyList : IEnumerable
+ {
+ int Count { get; }
+ T this[int index] { get; }
+ }
+
+ ///
+ /// A minimal read only list for .NET 4 implemented as a wrapper
+ /// around an IList.
+ ///
+ public class ReadOnlyList : IReadOnlyList
+ {
+ private readonly IList list;
+
+ public ReadOnlyList()
+ : this(new List())
+ {
+ }
+
+ public ReadOnlyList(IList list)
+ {
+ if (list == null)
+ throw new ArgumentNullException("list");
+
+ this.list = list;
+ }
+
+ #region IEnumerable implementation
+ public IEnumerator GetEnumerator()
+ {
+ return list.GetEnumerator();
+ }
+ #endregion
+
+ #region IEnumerable implementation
+ System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
+ {
+ return list.GetEnumerator();
+ }
+ #endregion
+
+ #region IReadOnlyList implementation
+ public int Count { get { return list.Count; } }
+
+ public T this[int index] { get { return list[index]; } }
+ #endregion
+ }
+}