In order to compile the SILC Plugin (instead of the SILC Client), pass the following options to configure: --enable-silc-plugin --without-silc-includes Depending on your OS/architecture you may also need to pass: --with-pic --without-pthreads For installing the SILC Plugin to the appropriate directories, you have to define the following paths (assuming Irssi is installed to /usr) --prefix=/usr --with-simdir=/usr/lib/irssi --with-helpdir=/usr/share/irssi/help