OK, so I've been working on this for hours. I've found a couple of posts here, but nothing that actually resolves the problem. So, let me try it again... I have an MVC2 app using Ninject and a custom membership provider. If I try and inject the provider using the ctor, I get an error: 'No parameterless constructor defined for this object.' public class MyMembershipProvider : MembershipProvider { IMyRepository _repository; public MyMembershipProvider(IMyRepository repository) { _repository = repository; } I've also been playing around with factories and Initialize(), but everything is coming up blanks. Any thoughts/examples?