Moq - Setting HttpResponse

I am trying to Mock a HttpResponse for a ConrollerContext object using MVC 4, Moq 4 and C# 4.5

My code is here:

var context = new Mock<HttpContextBase>();
var response = new Mock<HttpResponseBase>();

context.SetupProperty(c => c.Response = response);

I have tried using Setup().Returns() and SetupGet() but I keep getting the following error:

"Property or Indexer 'System.Web.HttpContextBase.Response' cannot be assigned to -- it is read only.

I have tried Googling this and searching on this website, but I can't seem to find the answer.