Index: app/drivers/Makefile.am
--- app/drivers/Makefile.am.orig
+++ app/drivers/Makefile.am
@@ -27,6 +27,10 @@ if DRIVER_SDL
   libdrivers_a_SOURCES += sdl-output.c
 endif
 
+if DRIVER_SNDIO
+  libdrivers_a_SOURCES += sndio-output.c sndio-input.c
+endif
+
 AM_CPPFLAGS = -I..
 
 EXTRA_DIST = dsound-output.c