Scoped kind variables do not work with default associated types

I have

{-# LANGUAGE PolyKinds, TypeFamilies, ScopedTypeVariables #-}

module Bug where

class C (a :: k) where
  type F (a :: k)
  type F (a :: k) = Int

Compiling gives me

Bug.hs:7:11:
    The signature specified kind ‘k1’, but ‘a’ has kind ‘k2’
    In the type ‘(a :: k)’
    In the type instance declaration for ‘F’
    In the class declaration for ‘C’

The error is on the line declaring the default associated type for F. This happens in both 7.8.2 and HEAD. Having !ScopedTypeVariables causes no change, but I put it in the example to emphasize that adding !ScopedTypeVariables is not the solution.

Trac metadata

Trac field	Value
Version	7.8.2
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
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