Dereferencing array elements with AllegroCL - how?

UFFI 1.3.1 and AllegroCL 6.2 trial.

  CL-USER(2): (uffi:deref-array (uffi:allocate-foreign-object :int 4) :int 2)
  Error: slot name 2 can't be used for type
         #S(FOREIGN-FUNCTIONS::SIZED-FTYPE-PRIM :KIND :INT :WIDTH 4
                                                :OFFSET 0 :ALIGN 4)
    [condition type: SIMPLE-ERROR]

Is that not the right way to create an array and then dereference one
of its elements? It works with CMUCL, LW, SBCL so I thought I was on
the right track.

Thanks,
Edi.