diff --git a/Source/AffineThreadPool.cs b/Source/AffineThreadPool.cs
index 96512f5..1b2489d 100644
--- a/Source/AffineThreadPool.cs
+++ b/Source/AffineThreadPool.cs
@@ -19,10 +19,10 @@ License along with this library
 #endregion
 
 using System;
-using System.Threading;
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Runtime.InteropServices;
+using System.Threading;
 
 namespace Nuclex.Support {
 
@@ -88,7 +88,11 @@ namespace Nuclex.Support {
       // as we may run into situations where multiple operations need to be atomic.
       // We keep track of the threads we've created just for good measure; not actually
       // needed for any core functionality.
+#if XBOX360
       workAvailable = new Semaphore();
+#else
+      workAvailable = new System.Threading.Semaphore(0, Processors);
+#endif
       userWorkItems = new Queue<UserWorkItem>(Processors * 4);
       workerThreads = new List<Thread>(Processors);
       inUseThreads = 0;
@@ -299,7 +303,11 @@ namespace Nuclex.Support {
     /// <summary>
     ///   Used to let the threads in the thread pool wait for new work to appear.
     /// </summary>
+#if XBOX360
     private static Semaphore workAvailable;
+#else
+    private static System.Threading.Semaphore workAvailable;
+#endif
     /// <summary>List of all worker threads at the disposal of the thread pool.</summary>
     private static List<Thread> workerThreads;
     /// <summary>Number of threads currently active.</summary>
diff --git a/Source/Parsing/CommandLine.cs b/Source/Parsing/CommandLine.cs
index bb8213f..9662f99 100644
--- a/Source/Parsing/CommandLine.cs
+++ b/Source/Parsing/CommandLine.cs
@@ -99,13 +99,13 @@ namespace Nuclex.Support.Parsing {
 
     /// <summary>Initializes a new command line</summary>
     /// <param name="argumentList">List containing the parsed arguments</param>
-    private CommandLine(List<Argument> argumentList) :
+    private CommandLine(IList<Argument> argumentList) :
       this(argumentList, WindowsModeDefault) { }
 
     /// <summary>Initializes a new command line</summary>
     /// <param name="argumentList">List containing the parsed arguments</param>
     /// <param name="windowsMode">Whether the / character initiates an argument</param>
-    private CommandLine(List<Argument> argumentList, bool windowsMode) {
+    private CommandLine(IList<Argument> argumentList, bool windowsMode) {
       this.arguments = argumentList;
       this.windowsMode = windowsMode;
     }
@@ -298,7 +298,7 @@ namespace Nuclex.Support.Parsing {
     }
 
     /// <summary>Options that were specified on the command line</summary>
-    private List<Argument> arguments;
+    private IList<Argument> arguments;
     /// <summary>Whether the / character initiates an argument</summary>
     private bool windowsMode;
 
diff --git a/Source/Semaphore.Test.cs b/Source/Semaphore.Test.cs
index d1e8b68..cb44f38 100644
--- a/Source/Semaphore.Test.cs
+++ b/Source/Semaphore.Test.cs
@@ -29,7 +29,10 @@ using NUnit.Framework;
 namespace Nuclex.Support {
 
   /// <summary>Unit Test for the Semaphore class</summary>
-  [TestFixture]
+  [
+    TestFixture,
+    Obsolete("Not obsolete, but prevents warning when using custom Semaphore on Windows")
+  ]
   public class SemaphoreTest {
 
     /// <summary>
diff --git a/Source/Semaphore.cs b/Source/Semaphore.cs
index 5c6e4f6..4f6b3e9 100644
--- a/Source/Semaphore.cs
+++ b/Source/Semaphore.cs
@@ -56,6 +56,9 @@ namespace Nuclex.Support {
   ///     become eligible for execution.
   ///   </para>
   /// </remarks>
+#if !XBOX360
+  [Obsolete("Prefer the normal semaphore on Windows builds.")]
+#endif
   public class Semaphore : WaitHandle {
 
     /// <summary>Initializes a new semaphore</summary>