In order to compile the SILC Plugin (instead of the SILC Client), pass the following options to configure, if your Irssi is installed into /usr: --prefix=/usr --with-silc-plugin --without-silc-includes If your Irssi is installed in some other location than /usr, then pass its location to --prefix and --with-silc-plugin, for example: --prefix=/usr/local --with-silc-plugin=/usr/local/lib/irssi --without-silc-includes Depending on your OS/architecture you may also need to pass the following options to configure: --with-pic --without-pthreads