diff --git a/configure.ac b/configure.ac
index 9032bf89..4cf0cb48 100644
--- a/configure.ac
+++ b/configure.ac
@@ -314,6 +314,7 @@ AC_SUBST(LIBCDIO_DEPS)
 AC_SUBST(LIBISO9660_LIBS)
 AC_SUBST(LIBUDF_LIBS)
 
+SED_EXTENDED_RE_FLAG='-r'
 dnl Libtool flag for strict linkage
 LT_NO_UNDEFINED=
 
@@ -325,6 +326,7 @@ case $host_os in
        ##     [Define 1 if you have AIX CD-ROM support])
        ;;
      darwin[[6-9]].*|darwin1[[0-2]].*)
+       SED_EXTENDED_RE_FLAG='-E'
        AC_CHECK_HEADERS(IOKit/IOKitLib.h CoreFoundation/CFBase.h, 
                         [have_iokit_h="yes"])
        if test "x$have_iokit_h" = "xyes" ; then 
@@ -414,12 +416,14 @@ int has_timeout=sizeof(test.timeout);],
 	enable_cdda_player="no"
 	;;
      freebsd4.*|freebsd5.*|freebsd[[6-9]].*|dragonfly*|kfreebsd*)
+       SED_EXTENDED_RE_FLAG='-E'
      	AC_DEFINE([HAVE_FREEBSD_CDROM], [1], 
                   [Define 1 if you have FreeBSD CD-ROM support])
  	LIBS="$LIBS -lcam"
   	cd_drivers="${cd_drivers}, FreeBSD "
 	;;
      netbsd*)
+        SED_EXTENDED_RE_FLAG='-E'
      	AC_DEFINE([HAVE_NETBSD_CDROM], [1], 
                   [Define 1 if you have NetBSD CD-ROM support])
  	# LIBS="$LIBS -lcam"
@@ -438,6 +442,7 @@ int has_timeout=sizeof(test.timeout);],
 	;;
 esac
 
+AC_SUBST(SED_EXTENDED_RE_FLAG)
 AC_SUBST(LIBCDIO_CFLAGS)
 AC_SUBST(LIBISO9660_CFLAGS)
 AC_SUBST(LT_NO_UNDEFINED)
diff --git a/include/cdio/Makefile.am b/include/cdio/Makefile.am
index da4c4f42..f0be71ad 100644
--- a/include/cdio/Makefile.am
+++ b/include/cdio/Makefile.am
@@ -22,7 +22,7 @@
 cdio_config.h: $(top_builddir)/config.h
 	@echo  '#ifndef __CDIO_CONFIG_H__' > cdio_config.h
 	@echo  '#define __CDIO_CONFIG_H__' >> cdio_config.h
-	@@SED@ -re 's/^(#[ \t]*define) /\1 CDIO_/' $(top_builddir)/config.h >>cdio_config.h
+	@@SED@ @SED_EXTENDED_RE_FLAG@ -e 's/^(#[ \t]*define) /\1 CDIO_/' $(top_builddir)/config.h >>cdio_config.h
 	@echo '#endif /* #ifndef CDIO_CONFIG_H */' >>cdio_config.h
 
 libcdioincludedir=$(includedir)/cdio