diff --git a/Octokit.Tests/Octokit.Tests-Portable.csproj b/Octokit.Tests/Octokit.Tests-Portable.csproj
index 54fcc789..489ad5be 100644
--- a/Octokit.Tests/Octokit.Tests-Portable.csproj
+++ b/Octokit.Tests/Octokit.Tests-Portable.csproj
@@ -39,7 +39,9 @@
     <Reference Include="System" />
     <Reference Include="System.Core" />
     <Reference Include="Microsoft.CSharp" />
-    <Reference Include="System.Net.Http" />
+    <Reference Include="System.Net.Http">
+      <Private>True</Private>
+    </Reference>
     <Reference Include="System.Xml.Linq" />
     <Reference Include="NSubstitute">
       <HintPath>..\packages\NSubstitute.1.8.0.0\lib\net40\NSubstitute.dll</HintPath>