This is a cherry-pick of Git commit 813fc02af8723421eeeadcb13eb361e2e44416ca from the Virtualenv repo. It fixes https://github.com/pypa/virtualenv/issues/378.
This is a cherry-pick of Git commit 813fc02af8723421eeeadcb13eb361e2e44416ca from the Virtualenv repo. It fixes https://github.com/pypa/virtualenv/issues/378.