Rewrite rule not firing for typeclass

The following rewrite rule fires for a normal function, but fails to fire as the method of a typeclass.

{-# OPTIONS_GHC -O -ddump-rule-firings #-}
module RewriteProblems where

{-# RULES
"rewrite/class"    forall a. id1 (id1 a) = RDUnit
"rewrite/static"   forall a. id1' (id1' a) = RDUnit
   #-}

class Ider a where
    id1 :: a -> a

data RewriteD = RDUnit

instance Ider RewriteD where
    {-# INLINE[1] id1 #-}
    id1 a = RDUnit

classTest :: RewriteD
classTest = id1 (id1 RDUnit)

staticTest :: RewriteD
staticTest = id1' (id1' RDUnit)

{-# INLINE[1] id1' #-}
id1' :: RewriteD -> RewriteD
id1' a = RDUnit

Trac metadata

Trac field	Value
Version	7.4.1
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
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