Deriving Data for existentially quantified types

I cannot derive Data for:

data EqBox where
  EB :: forall e . (Data e, Eq e) => e -> EqBox

I am getting such error:

   Ambiguous type variable `e' in the constraints:
      (Eq e) arising from a use of `EB' at Test.hs:11:1-28
      (Data e) arising from a use of `k' at Test.hs:11:1-28
    Probable fix: add a type signature that fixes these type variable(s)
    In the first argument of `z', namely `EB'
    In the first argument of `k', namely `z EB'
    In the expression: k (z EB)
    When typechecking the code for  `gunfold'
      in a standalone derived instance for `Data EqBox':
      To see the code I am typechecking, use -ddump-deriv

Trac metadata

Trac field	Value
Version	7.1
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
Test case
Differential revisions
BlockedBy
Related
Blocking
CC	mmitar@gmail.com
Operating system
Architecture