diff --git a/dir.props b/dir.props
index 5be8a0aeab02..822ca03bbc95 100644
--- a/dir.props
+++ b/dir.props
@@ -1,10 +1,16 @@
 <Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <!-- Build Tools Version -->
+  <PropertyGroup>
+    <BuildToolsVersion>1.0.16-prerelease</BuildToolsVersion>
+  </PropertyGroup>
+
   <!-- Common repo directories -->
   <PropertyGroup>
     <ProjectDir>$(MSBuildThisFileDirectory)</ProjectDir>
     <SourceDir>$(ProjectDir)src\</SourceDir>
     <BinDir>$(ProjectDir)bin\</BinDir>
     <ToolsDir>$(BinDir)tools\</ToolsDir>
+    <TestWorkingDir>$(BinDir)tests\</TestWorkingDir>
     <PackagesDir>$(SourceDir)packages\</PackagesDir>
   </PropertyGroup>
 
@@ -18,10 +24,9 @@
 
   <!-- Common build tool properties -->
   <PropertyGroup>
-    <BuildToolsVersion>1.0.15-prerelease</BuildToolsVersion>
     <BuildToolsInstallSempahore>$(ToolsDir)BuildTools.$(BuildToolsVersion).installed.semaphore</BuildToolsInstallSempahore>
 
     <BuildToolsTargetInputs>$(MSBuildThisFileFullPath);$(MSBuildThisFileDirectory)build.proj</BuildToolsTargetInputs>
     <BuildToolsTargetOutputs>$(BuildToolsInstallSempahore)</BuildToolsTargetOutputs>
-  </PropertyGroup>  
+  </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/Common/tests/XunitTraitsDiscoverers/XunitTraitsDiscoverers.csproj b/src/Common/tests/XunitTraitsDiscoverers/XunitTraitsDiscoverers.csproj
index 11dfbc47b5b6..3eead8239498 100644
--- a/src/Common/tests/XunitTraitsDiscoverers/XunitTraitsDiscoverers.csproj
+++ b/src/Common/tests/XunitTraitsDiscoverers/XunitTraitsDiscoverers.csproj
@@ -11,6 +11,8 @@
     <OutputType>Library</OutputType>
     <AssemblyName>XunitTraitsDiscoverers</AssemblyName>
     <RootNamespace>Xunit.TraitDiscoverers</RootNamespace>
+    <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
+    <TargetFrameworkProfile>Profile7</TargetFrameworkProfile>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Debug|AnyCPU'">
     <DebugSymbols>true</DebugSymbols>
diff --git a/src/System.Linq.Parallel/tests/System.Linq.Parallel.Tests.csproj b/src/System.Linq.Parallel/tests/System.Linq.Parallel.Tests.csproj
index 3ce3d096aa48..3244c8640eac 100644
--- a/src/System.Linq.Parallel/tests/System.Linq.Parallel.Tests.csproj
+++ b/src/System.Linq.Parallel/tests/System.Linq.Parallel.Tests.csproj
@@ -105,7 +105,9 @@
       <Private>True</Private>
     </Reference>
     <Reference Include="xunit.assert">
+      <HintPath>..\..\packages\xunit.assert.2.0.0-beta5-build2785\lib\portable-net45+aspnetcore50+win+wpa81+wp80+monoandroid+monotouch10\xunit.assert.dll</HintPath>
       <Private>True</Private>
+    </Reference>
     <Reference Include="xunit.core">
       <HintPath>..\..\packages\xunit.core.2.0.0-beta5-build2785\lib\portable-net45+aspnetcore50+win+wpa81+wp80+monotouch+monoandroid\xunit.core.dll</HintPath>
       <Private>True</Private>
diff --git a/src/System.Reflection.Metadata/tests/System.Reflection.Metadata.Tests.csproj b/src/System.Reflection.Metadata/tests/System.Reflection.Metadata.Tests.csproj
index 550d8a6e7518..895c7acfe727 100644
--- a/src/System.Reflection.Metadata/tests/System.Reflection.Metadata.Tests.csproj
+++ b/src/System.Reflection.Metadata/tests/System.Reflection.Metadata.Tests.csproj
@@ -36,6 +36,7 @@
     <Reference Include="System.Collections">
       <HintPath>..\..\packages\System.Collections.4.0.10-beta-22412\lib\portable-wpa80+win80+net45+aspnetcore50\System.Collections.dll</HintPath>
       <Private>False</Private>
+    </Reference>
     <Reference Include="System.Collections.Immutable, Version=1.1.32.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL">
       <SpecificVersion>False</SpecificVersion>
       <HintPath>..\..\packages\System.Collections.Immutable.1.1.32-beta\lib\portable-net45+win8+wp8+wpa81\System.Collections.Immutable.dll</HintPath>
@@ -185,6 +186,7 @@
     <Service Include="{82A7F48D-3B50-4B1E-B82E-3ADA8210C358}" />
   </ItemGroup>
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.targets))\dir.targets" />
+  <Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
     <PropertyGroup>
       <ErrorText>This project references NuGet package(s) that are missing on this computer. Enable NuGet Package Restore to download them.  For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}.</ErrorText>
     </PropertyGroup>
diff --git a/src/dirs.proj b/src/dirs.proj
index 0099d21d66e2..47df91ac137d 100644
--- a/src/dirs.proj
+++ b/src/dirs.proj
@@ -29,6 +29,13 @@
 
   <Import Project="$(ToolsDir)packages.targets" Condition="Exists('$(ToolsDir)packages.targets')" />
   <Target Name="BuidDirPackages" AfterTargets="Build" DependsOnTargets="BuildPackages" />
+
+  <ItemGroup>
+    <DisabledTestAssembly Include="System.Threading.Tasks.Dataflow.Tests" />
+    <DisabledTestAssembly Include="System.Linq.Parallel.Tests" />
+
+    <_SkipTestAssemblies Include="@(DisabledTestAssembly)" />
+  </ItemGroup>
   
   <Import Project="$(ToolsDir)tests.targets" Condition="Exists('$(ToolsDir)tests.targets')" />
   <Target Name="RunDirTests" AfterTargets="Build" DependsOnTargets="RunTests" />