diff --git a/source/Cosmos.Core.Tests/Cosmos.Core.Tests.csproj b/source/Cosmos.Core.Tests/Cosmos.Core.Tests.csproj
index b2e5bc8db..40b4454e0 100644
--- a/source/Cosmos.Core.Tests/Cosmos.Core.Tests.csproj
+++ b/source/Cosmos.Core.Tests/Cosmos.Core.Tests.csproj
@@ -57,7 +57,9 @@
     <CodeAnalysisRuleSet>MinimumRecommendedRules.ruleset</CodeAnalysisRuleSet>
   </PropertyGroup>
   <ItemGroup>
-    <Reference Include="Microsoft.VisualStudio.QualityTools.UnitTestFramework, Version=10.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL" />
+    <Reference Include="nunit.framework">
+      <HintPath>..\..\Resources\Dependencies\NUnit\nunit.framework.dll</HintPath>
+    </Reference>
     <Reference Include="System" />
     <Reference Include="System.Core" />
     <Reference Include="System.Xml.Linq" />
diff --git a/source/Cosmos.Core.Tests/FieldOrderTests.cs b/source/Cosmos.Core.Tests/FieldOrderTests.cs
index 3e9de4bcd..9f5239d98 100644
--- a/source/Cosmos.Core.Tests/FieldOrderTests.cs
+++ b/source/Cosmos.Core.Tests/FieldOrderTests.cs
@@ -3,12 +3,11 @@ using System.Linq;
 
 using Cosmos.Debug.Common;
 using Cosmos.IL2CPU;
-
-using Microsoft.VisualStudio.TestTools.UnitTesting;
+using NUnit.Framework;
 
 namespace Cosmos.Core.Tests
 {
-    [TestClass]
+    [TestFixture]
     public class FieldOrderTests
     {
         // the memory stuff requires DataLookupEntry.DataBlock to be the first field