``` type Foo = delegate of unit -> unit let f1 = Foo(ignore) f1.Invoke() Foo(ignore).Invoke() ``` ``` Library.fs(9, 1): [FS0001] This expression was expected to have type 'Foo1' but here has type 'unit' ``` <img width="299" alt="screen shot 2018-09-07 at 16 59 43" src="https://user-images.githubusercontent.com/3923587/45223281-83879a80-b2bf-11e8-8352-96d98b0a0644.png">