Как исправить ошибку при установки Ruby gem'a sass?

ERROR: Could not find a valid gem 'libopenssl-ruby' (>= 0), here is why:
Unable to download data from https://rubygems.org/ - SSL_connect retur
ned=1 errno=0 state=SSLv3 read server certificate B: certificate verify failed (
https://api.rubygems.org/latest_specs.4.8.gz)