diff --git a/src/UnitTests/UnitTests-CUDA.csproj b/src/UnitTests/UnitTests-CUDA.csproj
index 598ce9a2..074df81c 100644
--- a/src/UnitTests/UnitTests-CUDA.csproj
+++ b/src/UnitTests/UnitTests-CUDA.csproj
@@ -16,7 +16,7 @@
     <SolutionDir Condition="$(SolutionDir) == '' Or $(SolutionDir) == '*Undefined*'">..\..\</SolutionDir>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <DefineConstants>TRACE;CUDA</DefineConstants>
+    <DefineConstants>TRACE;NATIVE;CUDA</DefineConstants>
     <OutputPath>..\..\out\CUDA\Windows\</OutputPath>
     <IntermediateOutputPath>..\..\obj\CUDA\Windows\x86\</IntermediateOutputPath>
     <BaseIntermediateOutputPath>..\..\obj\CUDA\Windows\x86\</BaseIntermediateOutputPath>
@@ -28,7 +28,7 @@
     <PlatformTarget>AnyCPU</PlatformTarget>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <DefineConstants>TRACE;DEBUG;CUDA</DefineConstants>
+    <DefineConstants>TRACE;DEBUG;NATIVE;CUDA</DefineConstants>
     <OutputPath>..\..\out\CUDA\Windows\</OutputPath>
     <IntermediateOutputPath>..\..\obj\CUDA\Windows\x86\</IntermediateOutputPath>
     <BaseIntermediateOutputPath>..\..\obj\CUDA\Windows\x86\</BaseIntermediateOutputPath>
diff --git a/src/UnitTests/UnitTests-MKL.csproj b/src/UnitTests/UnitTests-MKL.csproj
index bbd73bbf..07bd43ec 100644
--- a/src/UnitTests/UnitTests-MKL.csproj
+++ b/src/UnitTests/UnitTests-MKL.csproj
@@ -16,7 +16,7 @@
     <SolutionDir Condition="$(SolutionDir) == '' Or $(SolutionDir) == '*Undefined*'">..\..\</SolutionDir>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <DefineConstants>TRACE;NATIVE</DefineConstants>
+    <DefineConstants>TRACE;NATIVE;MKL</DefineConstants>
     <OutputPath>..\..\out\MKL\Windows\</OutputPath>
     <IntermediateOutputPath>..\..\obj\MKL\Windows\x86\</IntermediateOutputPath>
     <BaseIntermediateOutputPath>..\..\obj\MKL\Windows\x86\</BaseIntermediateOutputPath>
@@ -28,7 +28,7 @@
     <PlatformTarget>AnyCPU</PlatformTarget>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <DefineConstants>TRACE;DEBUG;NATIVE</DefineConstants>
+    <DefineConstants>TRACE;DEBUG;NATIVE;MKL</DefineConstants>
     <OutputPath>..\..\out\MKL\Windows\</OutputPath>
     <IntermediateOutputPath>..\..\obj\MKL\Windows\x86\</IntermediateOutputPath>
     <BaseIntermediateOutputPath>..\..\obj\MKL\Windows\x86\</BaseIntermediateOutputPath>
diff --git a/src/UnitTests/UseLinearAlgebraProvider.cs b/src/UnitTests/UseLinearAlgebraProvider.cs
index d45957e8..00266687 100644
--- a/src/UnitTests/UseLinearAlgebraProvider.cs
+++ b/src/UnitTests/UseLinearAlgebraProvider.cs
@@ -39,10 +39,11 @@ namespace MathNet.Numerics.UnitTests
         public void BeforeTest(TestDetails testDetails)
         {
 #if !NET35 && NATIVE
+#if MKL
             Control.UseNativeMKL();
-#endif
-#if CUDA
+#elif CUDA
             Control.UseNativeCUDA();
+#endif
 #endif
         }