- field=catalogue.fields.EbookField('cover_api_thumb', max_length=255, upload_to=catalogue.models.book.UploadToPath('book/cover_api_thumb/%s.jpg'), null=True, verbose_name='cover thumbnail for API', blank=True),
+ field=models.FileField(max_length=255, upload_to=catalogue.fields.UploadToPath('book/cover_api_thumb/%s.jpg'), null=True, verbose_name='cover thumbnail for API', blank=True),