diff --git a/grouptools/GNUmakefile b/grouptools/GNUmakefile
new file mode 100644
index 0000000..4120c67
--- /dev/null
+++ b/grouptools/GNUmakefile
@@ -0,0 +1,30 @@
+include GNUmakevars
+
+CONFDIR=../../configure
+CONFDIR_exists=$(shell [ -d $(CONFDIR) ] && echo ok)
+
+all: configure grouplist groupmatch
+
+clean:
+	rm grouplist groupmatch
+
+install: \
+	$(BINDIR)/grouplist \
+	$(BINDIR)/groupmatch \
+
+
+%: %.pl customize
+	sh ./customize < $< > $@
+	chmod +x $@
+
+customize: configure
+	sh ./configure
+
+ifeq ($(CONFDIR_exists),ok)
+
+configure: $(CONFDIR)/start $(CONFDIR)/perl $(CONFDIR)/finish
+	cat $^ > $@
+
+endif
+
+include GNUmakerules
diff --git a/grouptools/grouplist b/grouptools/grouplist.pl
similarity index 100%
rename from grouptools/grouplist
rename to grouptools/grouplist.pl
diff --git a/grouptools/groupmatch b/grouptools/groupmatch.pl
similarity index 100%
rename from grouptools/groupmatch
rename to grouptools/groupmatch.pl