--- configure.ac.orig	Mon May  7 10:49:43 2007
+++ configure.ac	Mon May  7 10:55:56 2007
@@ -73,7 +73,7 @@
 AC_HEADER_STDC
 AC_HEADER_SYS_WAIT
 AC_CHECK_HEADERS(fcntl.h limits.h strings.h time.h sys/ioctl.h sys/time.h unistd.h)
-AC_CHECK_HEADERS(linux/ppdev.h sys/mman.h sys/select.h sys/types.h)
+AC_CHECK_HEADERS(linux/ppdev.h dev/ppbus/ppi.h sys/mman.h sys/select.h sys/types.h)
 AC_CHECK_HEADERS(sys/resource.h stdint.h sched.h)
 
 dnl Checks for typedefs, structures, and compiler characteristics.