diff --git a/src/etc/inc/plugins.inc.d/dpinger.inc b/src/etc/inc/plugins.inc.d/dpinger.inc
index 10fc6a125..12b293149 100644
--- a/src/etc/inc/plugins.inc.d/dpinger.inc
+++ b/src/etc/inc/plugins.inc.d/dpinger.inc
@@ -192,9 +192,11 @@ function dpinger_configure_do($verbose = false, $gwname = null)
              * then the ICMP6 response would not find its way back home.
              */
             if (is_linklocal($gateway['monitor']) && strpos($gateway['monitor'], '%') === false) {
+                /* XXX 'if' can be wrong for IPv6 */
                 $gateway['monitor'] .= "%{$gateway['if']}";
             }
             if (is_linklocal($gateway['gateway']) && strpos($gateway['gateway'], '%') === false) {
+                /* XXX 'if' can be wrong for IPv6 */
                 $gateway['gateway'] .= "%{$gateway['if']}";
             }