Discrepancy in type synonym definition and usage

Minor consistency issue, the following compiles fine (note parentheses):

type Alg f a = f a -> a

initial :: Alg(f) a
initial = undefined

But changing the definition to mirror its use:

type Alg(f) a = f a -> a

initial :: Alg(f) a
initial = undefined

and it fails with:

    Unexpected type ‘f’
    In the type declaration for ‘Alg’
    A type declaration should have form
      type Alg a b c = ...
Failed, modules loaded: none.

Trac metadata

Trac field	Value
Version	7.8.3
Type	Bug
TypeOfFailure	OtherFailure
Priority	lowest
Resolution	Unresolved
Component	Compiler (Parser)
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