How to add a 'greek' character in the path using cURL?

Question

I have a Makefile where one of many tasks is to upload a file using cURL, one of these files, has a greek character in the name and when I try to upload using cURL, I receive this error:

curl: (43) A libcurl function was given a bad argument

I'm using Mac OS X terminal.

Here a snippet of my Makefile

FILENAME=SomeFile α.app

my_upload_task:
  /usr/bin/curl "http://host.com/api/upload" \
  -F 'file=@$(BASE_DIR)development/$(FILENAME).bin' \
  -F message='Upload some file to api'

Any suggestions are welcome! Thanks.