How to install prerelease version using pipenv?

I tried installing Django prelease using pipenv, here are the steps I followed

• pipenv lock --pre

• pipenv install --pre Django

And when I check the pip freeze it shows me correct version of the Django

(fiobot-dPUFI04r) simon@ENGINE:~/Nightybuild/fiobot$ pip freeze
Django==2.0b1
gunicorn==19.7.1
pytz==2017.2

However when I looked into Pipfile.lock it shows this "version": "==1.11.6"

I deployed to Heroku my code doesn’t run because my code needs pre release version of Django how to solve this ?

My environment

1. OS Type: Ubuntu 16.04 LTS
2. Python version: Python 3.6.3
3. Pipenv version: pipenv, version 8.2.7

[erinxocon]

It looks like the allow_prerelease environment marker isn’t respected when you do pipenv lock. You have to do pipenv lock --pre or pipenv install --pre django for now. pipenv install relocks the file by default so it uses the --pre flag. For now you’ll have to use either of those two methods until we get the bug fixed!

[rajasimon]

Oh here is my Pipfile. And I can’t mention the exact version of Django in package because that’s not working.

[[source]]

url = "https://pypi.python.org/simple"
verify_ssl = true
name = "pypi"


[dev-packages]



[packages]

django = "*"
gunicorn = "*"


[requires]

python_version = "3.6"


[pipenv]

allow_prereleases = true