Does Google Backup save SMS messages which are stored on the SIM card?

Does Google Backup save SMS which are stored on the SIM card? I always took for granted the answer is yes, especially because it saves the contacts which are stored on the SIM card, and it doesn't make much sense for a backup utility to miss such important data as SIM sms. However some research revealed that many other SMS backup apps miss these messages, and I couldn't find any explicit info about Google backup.