vs2015 keeps removing hintpath from csproj

In order to get my unit test project to build in Jenkins, I had to add a reference to:

<ItemGroup>
<Reference Include="Microsoft.VisualStudio.QualityTools.UnitTestFramework, Version=10.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL">
  <SpecificVersion>False</SpecificVersion>
  <HintPath>..\lib\Microsoft.VisualStudio.QualityTools.UnitTestFramework.dll</HintPath>
</Reference>
<Reference Include="System" />

However, vs2015.2 keeps removing the hint path. In fact, if I undo it, it immediately comes back. How can I prevent v2015.2 from removing the hint path from the CSPROJ? Or, is there a workaround / better way?