Repair issue #220.
Repair issue #220.

kwlzn/pex,snyaggarwal/pex,snyaggarwal/pex,sixninetynine/pex,jsirois/pex,jsirois/pex,kwlzn/pex,rouge8/pex,rouge8/pex,sixninetynine/pex,pantsbuild/pex,pantsbuild/pex,mzdanieltest/pex,mzdanieltest/pex