ASP.NET Compiler complaining of mismatching framework versions with MiniProfiler

I have an MVC3 project that I upgraded from VS2010 to VS2012. The project also has a reference to MiniProfiler. Our application compiles and runs fine in VS2012 without any warnings/errors. Both assemblies load fine when running with IIS Express. When using the ASP.NET Compiler tool, however, I get the following warning: