head array-map! type check

[Kevin Ryde]

Running

    (array-map! (make-array 99 5) noop (make-array 99 5) (make-array 99 5))

Gives

    Backtrace:
    In current input:
       3: 0* [array-map! #(99 99 99 ...) #<primitive-procedure noop> ...]

    <unnamed port>:3:1: In procedure array-map! in expression (array-map! 
(make-array 99 5) noop ...):
    <unnamed port>:3:1: Wrong type (expecting uniform vector): #(#(99 99 99 99 
99))
ABORT: (wrong-type-arg)

Is there a good reason for this, or has some type checking gone
astray?