Precompiled headers issue: -c and -fpch-preprocess should be used together?

Folks, I'm using gcc-4.4.1(4.4.1-4ubuntu9 to be precise) on Ubuntu and
after trying to make PCH work properly for some time I found that
precompiled headers are not used if -c option used. Experimenting with
different options I discovered that it's the -fpch-preprocess option
which enables PCH in this case.

Is it an expected behavior? If yes, maybe it should be documented here
http://gcc.gnu.org/onlinedocs/gcc/Precompiled-Headers.html in order to
save some time for others :)

-- 
Best regards, Pavel