diff -Nur Mail-SpamAssassin-3.4.0.orig/lib/Mail/SpamAssassin/DnsResolver.pm Mail-SpamAssassin-3.4.0/lib/Mail/SpamAssassin/DnsResolver.pm
--- Mail-SpamAssassin-3.4.0.orig/lib/Mail/SpamAssassin/DnsResolver.pm	2014-02-07 01:36:28.000000000 -0700
+++ Mail-SpamAssassin-3.4.0/lib/Mail/SpamAssassin/DnsResolver.pm	2014-06-20 11:53:04.688979753 -0600
@@ -204,8 +204,10 @@
     @ns_addr_port = @{$self->{conf}->{dns_servers}};
     dbg("dns: servers set by config to: %s", join(', ',@ns_addr_port));
   } elsif ($res) {  # default as provided by Net::DNS, e.g. /etc/resolv.conf
-    @ns_addr_port = map(untaint_var("[$_]:" . $res->{port}),
-                        @{$res->{nameservers}});
+    my @ns = $res->UNIVERSAL::can('nameservers') ? $res->nameservers
+                                                 : @{$res->{nameservers}};
+    my $port = $res->UNIVERSAL::can('port') ? $res->port : $res->{port};
+    @ns_addr_port = map(untaint_var("[$_]:" . $port), @ns);
     dbg("dns: servers obtained from Net::DNS : %s", join(', ',@ns_addr_port));
   }
   return @ns_addr_port;