diff --git a/net/save_dns.cgi b/net/save_dns.cgi
index 876bb50be..29207db54 100755
--- a/net/save_dns.cgi
+++ b/net/save_dns.cgi
@@ -124,6 +124,19 @@ if (&foreign_installed("postfix") && $in{'hostname'} ne $old_hostname) {
 		&postfix::set_current_value("mydestination",
 					    join(", ", @mydests));
 		}
+	$old_domain = $old_hostname =~ /^[^\.]+\.(.*)$/ ? $1 :
+		      $old_fqdn =~ /^[^\.]+\.(.*)$/ ? $1 : undef;
+	$new_domain = $in{'hostname'} =~ /^[^\.]+\.(.*)$/ ? $1 :
+		      $new_fqdn =~ /^[^\.]+\.(.*)$/ ? $1 : undef;
+	if ($old_domain && $new_domain &&
+	    lc($old_domain) ne lc($new_domain)) {
+		$idx = &indexoflc("localhost.$old_domain", @mydests);
+		if ($idx >= 0) {
+			$mydests[$idx] = "localhost.$new_domain";
+			&postfix::set_current_value("mydestination",
+						    join(", ", @mydests));
+			}
+		}
 
 	# Update postfix myorigin
 	$myorigin = &postfix::get_current_value("myorigin");