Use "#!/usr/bin/env perl" as shebang line.
diff --git a/scripts/rename.pl b/scripts/rename.pl
index c29519e..fb42809 100755
--- a/scripts/rename.pl
+++ b/scripts/rename.pl
@@ -1,4 +1,4 @@
-#!/usr/bin/perl
+#!/usr/bin/env perl
 #
 # This file is part of mbed TLS (https://tls.mbed.org)
 #