return type checking is not right?

[osa1]

fun test(c: char): maybe<char>
  val c1 =
    match f(c)
      Just(c1) ->
        c1
      Nothing ->
        return Nothing // or `return test(c)`

  Just(c1)

fun f(c: char): maybe<char>
  Just(c)

fun main()
  ()

Output:

parse-iter.kk(7,16): type error: Nothing does not match the argument types
  context      :                Nothing
  term         :                Nothing
  inferred type: forall<a> maybe<a>
  expected type: char

Failed to compile parse-iter.kk

Is this expected?

The type checker does not seem to realize that return returns from the function, it doesn't generate a value for the enclosing expression.