diff --git a/csharp/msgpack.tests/BoxingPackerTests.cs b/csharp/msgpack.tests/BoxingPackerTests.cs
index da2209d..cd63129 100644
--- a/csharp/msgpack.tests/BoxingPackerTests.cs
+++ b/csharp/msgpack.tests/BoxingPackerTests.cs
@@ -1,33 +1,21 @@
-#define NUNIT
-
-using System;
-using System.Text;
-using System.Collections;
+using System;
 using System.Collections.Generic;
 using System.Linq;
-
-#if !NUNIT
-#error Currently, Not Supported
-using Microsoft.VisualStudio.TestTools.UnitTesting;
-#else
 using NUnit.Framework;
-using TestClass = NUnit.Framework.TestFixtureAttribute;
-using TestMethod = NUnit.Framework.TestAttribute;
-#endif
 
 namespace msgpack.tests
 {
-	[TestClass]
+	[TestFixture]
 	public class BoxingPackerTests
 	{
-		[TestMethod]
+		[Test]
 		public void NullTest ()
 		{
 			BoxingPacker packer = new BoxingPacker ();
 			Assert.IsNull (packer.Unpack (packer.Pack (null)));
 		}
 
-		[TestMethod]
+		[Test]
 		public void PrimitiveTypeTest ()
 		{
 			BoxingPacker packer = new BoxingPacker ();
@@ -38,7 +26,7 @@ namespace msgpack.tests
 			RoundtripTest<bool> (packer, false);
 		}
 
-		[TestMethod]
+		[Test]
 		public void ArrayTest ()
 		{
 			BoxingPacker packer = new BoxingPacker ();
@@ -54,7 +42,7 @@ namespace msgpack.tests
 			});
 		}
 
-		[TestMethod]
+		[Test]
 		public void MapTest ()
 		{
 			BoxingPacker packer = new BoxingPacker ();
diff --git a/csharp/msgpack.tests/ReaderWriterTests.cs b/csharp/msgpack.tests/ReaderWriterTests.cs
index 5faeae0..10c6f70 100644
--- a/csharp/msgpack.tests/ReaderWriterTests.cs
+++ b/csharp/msgpack.tests/ReaderWriterTests.cs
@@ -1,28 +1,13 @@
-#define NUNIT
-
-using System;
-using System.Text;
-using System.Collections.Generic;
-using System.Linq;
+using System;
 using System.IO;
-
-#if !NUNIT
-#error Currently, Not Supported
-using Microsoft.VisualStudio.TestTools.UnitTesting;
-#else
 using NUnit.Framework;
-using TestClass = NUnit.Framework.TestFixtureAttribute;
-using TestInitialize = NUnit.Framework.SetUpAttribute;
-using TestCleanup = NUnit.Framework.TearDownAttribute;
-using TestMethod = NUnit.Framework.TestAttribute;
-#endif
 
 namespace msgpack.tests
 {
-	[TestClass]
+	[TestFixture]
 	public class ReaderWriterTests
 	{
-		[TestMethod]
+		[Test]
 		public void SignedNumberTest ()
 		{
 			long[] nums = new long[]{
@@ -91,7 +76,7 @@ namespace msgpack.tests
 			}, expectedBytes);
 		}
 
-		[TestMethod]
+		[Test]
 		public void UnsignedNumberTest ()
 		{
 			ulong[] nums = new ulong[]{
@@ -142,7 +127,7 @@ namespace msgpack.tests
 			}, expectedBytes);
 		}
 
-		[TestMethod]
+		[Test]
 		public void NilTest ()
 		{
 			byte[] expectedBytes = new byte[] {
@@ -157,7 +142,7 @@ namespace msgpack.tests
 			}, expectedBytes);
 		}
 
-		[TestMethod]
+		[Test]
 		public void BooleanTest ()
 		{
 			byte[] expectedBytes = new byte[] {
@@ -175,7 +160,7 @@ namespace msgpack.tests
 			}, expectedBytes);
 		}
 
-		[TestMethod]
+		[Test]
 		public void FloatingPointTest ()
 		{
 			byte[] expectedBytes = new byte[] {
@@ -196,7 +181,7 @@ namespace msgpack.tests
 			}, expectedBytes);
 		}
 
-		[TestMethod]
+		[Test]
 		public void RawTest ()
 		{
 			Random rnd = new Random ();
@@ -241,7 +226,7 @@ namespace msgpack.tests
 			}, expectedBytes);
 		}
 
-		[TestMethod]
+		[Test]
 		public void ArrayMapRawHeaderTest ()
 		{
 			int[] list = new int[] {
diff --git a/csharp/msgpack.tests/msgpack.tests.csproj b/csharp/msgpack.tests/msgpack.tests.csproj
index e610dd8..5d27a80 100644
--- a/csharp/msgpack.tests/msgpack.tests.csproj
+++ b/csharp/msgpack.tests/msgpack.tests.csproj
@@ -35,7 +35,6 @@
     <StartupObject />
   </PropertyGroup>
   <ItemGroup>
-    <Reference Include="Microsoft.VisualStudio.QualityTools.UnitTestFramework, Version=10.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL" />
     <Reference Include="nunit.framework, Version=2.5.10.11092, Culture=neutral, PublicKeyToken=96d09a1eb7f44a77, processorArchitecture=MSIL">
       <SpecificVersion>False</SpecificVersion>
     </Reference>