diff -Nur Mail-DMARC-1.20141206/lib/Mail/DMARC/Base.pm Mail-DMARC-1.20141206_bz10318/lib/Mail/DMARC/Base.pm
--- Mail-DMARC-1.20141206/lib/Mail/DMARC/Base.pm	2014-12-06 07:56:07.000000000 +0100
+++ Mail-DMARC-1.20141206_bz10318/lib/Mail/DMARC/Base.pm	2017-05-20 13:19:53.585378458 +0200
@@ -187,6 +187,7 @@
 
 sub is_valid_domain {
     my ( $self, $domain ) = @_;
+    return 0 unless $domain;
     return 0 if $domain !~ /^$RE{net}{domain}{-rfc1101}{-nospace}$/x;
     my $tld = ( split /\./, $domain )[-1];
     return 1 if $self->is_public_suffix($tld);