GeneralizedNewtypeDeriving unusable on associated types

This code:

{-# LANGUAGE GeneralizedNewtypeDeriving #-}

class C c where
  data F c r

instance C Int where
  newtype F Int r = F (IO r) deriving (Functor)

fails to compile with the following message:

    Derived instance `Functor (F Int)'
      requires illegal partial application of data type family F
    In the newtype instance declaration for `F'

This might be related to #4185 (closed), but then it is marked as fixed in GHC 7.6.2, and I experience my error on 7.6.3.

Trac metadata

Trac field	Value
Version	7.6.3
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
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GeneralizedNewtypeDeriving unusable on associated types