Reverse charge in gst

Dear Experts, According to the provisions in GST law if a registered dealer purchases from unregistered dealer then he has to pay GST on reverse charge basis and he has to issue tax invoice for GST on reverse charge. Now my query is that if a dealer with composition scheme Purchases from unregistered dealer then shall he be liable to pay GST on Reverse charge?? If YES then how can he issue tax invoice as composition dealer is not allowed to issue tax invoice ??