[Dovecot] Installation directories layout question

[Hunny Bunny]

Hello folkz,
I'm trying to compile and install Dovecot 1.2.10 from sources.
When I execute: 

./configure --prefix=/usr/local/dovecot
make
make install
 
I reasonably expect to find dovecot libraries in /usr/local/dovecot/lib but it puts them into
/usr/local/dovecot/lib/dovecot. It add this extra 'dovecot' at the end of almost every installation path.

Could somebody please clarify what extra configuration parameters should be set to make to change this strange dovecot installation directories layout.

Thank you very much in advance,

Alex