diff --git a/grouptools/GNUmakefile b/grouptools/GNUmakefile
index dc76e68..1c4bee3 100644
--- a/grouptools/GNUmakefile
+++ b/grouptools/GNUmakefile
@@ -30,7 +30,7 @@ endif
 
 GNUmakevars: GNUmakevars.sh
 	sh ./$^ > $@
-GNUmakerules: GNUmakerules.sh
-	sh ./$^ > $@
+GNUmakerules: GNUmakerules.pl
+	perl ./$^ > $@
 
 include GNUmakerules
diff --git a/grouptools/GNUmakerules.pl b/grouptools/GNUmakerules.pl
new file mode 100644
index 0000000..8f30daa
--- /dev/null
+++ b/grouptools/GNUmakerules.pl
@@ -0,0 +1,8 @@
+#!/usr/bin/perl
+use warnings;
+use strict;
+
+print "\$(BINDIR)/%: %\n";
+print "\tcp \$^ \$@\n";
+print "\$(MAN1DIR)/%: %\n";
+print "\tcp \$^ \$@\n";