Why is my HTTP POST multipart/form-data wrong?

I am trying to re-create a HTTP-POST multipart/form-data request.

My HTTP-Body looks like this:

--nVenJ7H4puv
Content-Disposition: form-data; name="abc"

I am just a text.
--nVenJ7H4puv

My HTTP-Post request has the following headers:

"Content-Type: multipart/form-data; boundary=nVenJ7H4puv"

Even though according to my knowledge I did everything correctly, I get the reply from the webserver:

Failed to read the request form. Form section has invalid Content-Disposition value:

Can someone help me out what is wrong with this request?