diff --git a/Octokit.Tests/Octokit.Tests-Portable.csproj b/Octokit.Tests/Octokit.Tests-Portable.csproj
index 1b283b2d..5fb37353 100644
--- a/Octokit.Tests/Octokit.Tests-Portable.csproj
+++ b/Octokit.Tests/Octokit.Tests-Portable.csproj
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
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   <Import Project="..\packages\xunit.core.2.0.0\build\portable-net45+win+wpa81+wp80+monotouch+monoandroid+Xamarin.iOS\xunit.core.props" Condition="Exists('..\packages\xunit.core.2.0.0\build\portable-net45+win+wpa81+wp80+monotouch+monoandroid+Xamarin.iOS\xunit.core.props')" />
   <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />