diff --git a/configure.in b/configure.in
index 938c161f0..68d16f83e 100644
--- a/configure.in
+++ b/configure.in
@@ -89,6 +89,8 @@ AC_PROG_LIBTOOL
 AC_PROG_LEX
 AC_PROG_YACC
 AC_PROG_CC(intel)
+AC_PATH_PROG([GPERF], [gperf], [], [$PATH:/bin:/usr/bin:/usr/local/bin])
+AC_PATH_PROG([PERL], [perl], [], [$PATH:/bin:/usr/bin:/usr/local/bin])
 
 dnl ==========================
 dnl  check required libraries
diff --git a/src/libstrongswan/Makefile.am b/src/libstrongswan/Makefile.am
index 8e380156f..68e5497d2 100644
--- a/src/libstrongswan/Makefile.am
+++ b/src/libstrongswan/Makefile.am
@@ -19,20 +19,15 @@ libstrongswan_la_LIBADD = -lgmp -lpthread
 
 INCLUDES = -I$(top_srcdir)/src/libstrongswan
 EXTRA_DIST = asn1/oid.txt asn1/oid.pl
-DISTCLEANFILES = asn1/oid.c asn1/oid.h
+MAINTAINERCLEANFILES = asn1/oid.c asn1/oid.h
 
 if USE_LEAK_DETECTIVE
   libstrongswan_la_LIBADD += -ldl
   AM_CFLAGS = -DLEAK_DETECTIVE
 endif
 
-
-# TODO: get perl from ./configure
-PERL=perl
-
 asn1/oid.c :	asn1/oid.txt asn1/oid.pl
-	        cd asn1 && $(PERL) oid.pl
+		cd asn1 && $(PERL) oid.pl
 
 asn1/oid.h :	asn1/oid.txt asn1/oid.pl
 		cd asn1 && $(PERL) oid.pl
-
diff --git a/src/pluto/Makefile.am b/src/pluto/Makefile.am
index 3409140c6..9787f4973 100644
--- a/src/pluto/Makefile.am
+++ b/src/pluto/Makefile.am
@@ -30,10 +30,7 @@ pluto_LDADD = $(top_srcdir)/src/libfreeswan/libfreeswan.a $(top_srcdir)/src/libc
 _pluto_adns_LDADD = -lresolv $(top_srcdir)/src/libfreeswan/libfreeswan.a
 dist_man_MANS = pluto.8 ipsec.secrets.5
 EXTRA_DIST = oid.pl oid.txt
-DISTCLEANFILES = oid.c oid.h
-
-# TODO: get perl from ./configure
-PERL=perl
+MAINTAINERCLEANFILES = oid.c oid.h
 
 oid.c:	oid.txt oid.pl
 	$(PERL) oid.pl
diff --git a/src/starter/Makefile.am b/src/starter/Makefile.am
index 747459068..ff9c458b5 100644
--- a/src/starter/Makefile.am
+++ b/src/starter/Makefile.am
@@ -10,14 +10,11 @@ AM_CFLAGS = -DIPSEC_DIR=\"${ipsecdir}\" -DIPSEC_CONFDIR=\"${confdir}\" -DIPSEC_P
 starter_LDADD = loglite.o defs.o $(top_srcdir)/src/libfreeswan/libfreeswan.a
 EXTRA_DIST = parser.l parser.y keywords.txt ipsec.conf
 dist_man_MANS = ipsec.conf.5
-DISTCLEANFILES = lex.yy.c y.tab.c y.tab.h keywords.c
+MAINTAINERCLEANFILES = lex.yy.c y.tab.c y.tab.h keywords.c
 
 PLUTODIR=$(top_srcdir)/src/pluto
 OPENACDIR=$(top_srcdir)/src/openac
 
-# TODO: get gperf from ./configure
-GPERF=gperf
-
 lex.yy.c:	y.tab.c parser.l parser.y parser.h
 		$(LEX) parser.l
 
@@ -38,5 +35,3 @@ defs.o:		$(PLUTODIR)/defs.c $(PLUTODIR)/defs.h
 
 install-exec-local :
 		test -e "$(sysconfdir)/ipsec.conf" || $(INSTALL) ipsec.conf $(sysconfdir)/ipsec.conf
-
-