AFNItoNIFTI fails inside a mapnode

I have a function that returns afni files in the BRIK/HEAD format and I am having difficulties using AFNItoNIFTI function within a mapnode.

For example let’s say I have these afni files:

files = [file_A_+orig.BRIK, file_A_+orig.HEAD, file_B_+orig.BRIK, file_B_+orig.HEAD, file_C_+orig.BRIK, file_C_+orig.HEAD]

templates = {'afni_files': os.path.join(dir_afni, '*')}
select_files = Node(SelectFiles(templates), name='select_files')

convert = MapNode(AFNItoNIFTI(outputtype="NIFTI"), iterfield=['in_file'], name="convert")

wf.connect([(select_files, convert, [('afni_files', 'in_file')])])
wf.run()

Running this code returns the error:

TypeError: _overload_extension() takes exactly 2 arguments (3 given)

A workaround would be defining an out_file:

convert = MapNode(AFNItoNIFTI(outputtype="NIFTI",out_file='outfile.nii'), iterfield=['in_file'], name="convert")

this works, but then all NIFTI files in my mapflow folder will have the same name and I cannot determine if it’s A, B, C, etc.

 mapflow/
    _convert0/
       outfile.nii
    _convert1/
        outfile.nii
    _convert2/
        outfile.nii
 etc

Could someone please help me with this, as I have no clue what to do here? Is there a way to tell the mapnode to use the filename from the original BRIK/HEAD files?