How to follow systemd unit log?

I've found out I'm using the arguments in a bad order. Logs can actually be followed for a single unit by using:

journalctl -fu my_unit.service

Other working variations:

journalctl -f -u my_unit.service
journalctl -u my_unit.service -f

From journalctl manual:

-u, --unit=UNIT|PATTERN

Show messages for the specified systemd unit UNIT (such as a service unit), or for any of the units matched by PATTERN. If a pattern is specified, a list of unit names found in the journal is compared with the specified pattern and all that match are used.  For each unit name, a match is added for messages from the unit ("_SYSTEMD_UNIT=UNIT"), along with additional matches for messages from systemd and messages about coredumps for the specified unit.

This parameter can be specified multiple times.

-f, --follow

Show only the most recent journal entries, and continuously print new entries as they are appended to the journal.