diff --git a/scripts/extract-module-sig.pl b/scripts/extract-module-sig.pl
index faac6f2..0f161ea 100755
--- a/scripts/extract-module-sig.pl
+++ b/scripts/extract-module-sig.pl
@@ -1,4 +1,4 @@
-#!/usr/bin/perl -w
+#!/usr/bin/env perl
 #
 # extract-mod-sig <part> <module-file>
 #
@@ -12,6 +12,7 @@
 #  -k: Just the key ID
 #  -s: Just the crypto signature or PKCS#7 message
 #
+use warnings;
 use strict;
 
 die "Format: $0 -[0adnks] module-file >out\n"