zend framework2 - PDF is upload with application/octet-stream -

i have upload in application, user can upload pdf, png, jpg , gif files maximum file size of 2mb. when upload pdf larger size of 2mb error file has incorrect mimetype of 'application/octet-stream'

here can see filters validators:

    'type' => 'zend\inputfilter\fileinput', 'name' => $name, 'required' => $required, 'filters' => array(     array(         'name' => '\application\filter\file\renameupload',         'options' => array(             'target' => 'data/upload',             'use_upload_name' => true,             'count_up' => true,         ),     ), ), 'validators' => array(     array('name' => '\zend\validator\file\uploadfile'),     array(         'name' => '\zend\validator\file\extension',         'options' => array(             'extension' => array(                 'pdf',                 'jpg',                 'jpeg',                 'png',                 'gif',             ),         ),     ),     array(         'name' => 'zend\validator\file\size',         'options' => array(             'max' => '2mb',             'min' => '1kb',         ),     ),     array(         'name' => '\zend\validator\file\mimetype',         'options' => array(             'mimetype' => array(                 'application/pdf',                 'image/jpg',                 'image/jpeg',                 'image/png',                 'image/gif',             ),         ),     ), ), 

the renameupload own filter, checks if file same name exists , renames it, adding underscore number.

when add 'application/octet-stream' mimetype array upload works (with problem, file 2 times copied target directory)

anyone idea how can fix problem?