Enabling Linux Mode

[DerAlSem]

cd /usr/ports/emulators/linux_base
make install distclean

blah-blah-blah...

gmake[2]: Leaving directory `/usr/ports/archivers/rpm/work/rpm-3.0.6'
gmake[1]: Leaving directory `/usr/ports/archivers/rpm/work/rpm-3.0.6'
install  -o root -g wheel -m 444 
/usr/ports/archivers/rpm/work/rpm-3.0.6/doc/gendiff.1 /usr/local/man/man1
install  -o root -g wheel -m 444 
/usr/ports/archivers/rpm/work/rpm-3.0.6/doc/rpm.8 /usr/local/man/man8
install  -o root -g wheel -m 444 
/usr/ports/archivers/rpm/work/rpm-3.0.6/doc/rpm2cpio.8 /usr/local/man/man8
===>   Compressing manual pages for rpm-3.0.6_8
===>   Running ldconfig
/sbin/ldconfig -m /usr/local/lib
===>   Registering installation for rpm-3.0.6_8
===>   Returning to build of linux_base-7.1_5
===>  Configuring for linux_base-7.1_5
===>  Installing for linux_base-7.1_5
Linux mode is not enabled.
Loading linux kernel module now...
kldload: can't load linux: No such file or directory
The linux kernel module could not be loaded.
Please enable linux mode manually and retry.
*** Error code 1

What's going on? ;-(