Even socket units may fail, e.g. due to an out-of-memory situation, which may trigger errors like

systemd[1]: sshd.socket: Failed to fork off accept stub process: Cannot allocate memory

(The unit comes from Arch Linux openssh package.)

Since there is no "nice way to fix the root cause", setting Restart=always for the unit is needed to prevent losing access to headless hosts with difficult physical access, but that clause is valid only for services. Is there another way to have socket units always restart on failure?