Systemd, how to mount a device at boot, but disable automount after boot

Hi,

I do not seem to find a simple solution to the following problem:

I have a device listed in fstab, this should get mounted at boot. But if I manually unmount/remove the device after boot and if I present the device later on, systemd sees the device and automatically mounts it.

So how to prevent the latter (like pre-systemd behaviour). I can not use noauto in /etc/fstab since that will disable mounting at boot, which I still want to have.

Thanks