protected override void ApplyConfiguration(HttpConfiguration configuration) { // Add default route configuration.Routes.MapHttpRoute( name: "DefaultApi", routeTemplate: "api/{controller}/{id}", defaults: new { id = RouteParameter.Optional } ); // Set our own assembly resolver where we add the assemblies we need CustomControllerTypeResolver customHttpControllerTypeResolver = new CustomControllerTypeResolver(); configuration.Services.Replace(typeof(IHttpControllerTypeResolver), customHttpControllerTypeResolver); }