--- a/src/network/networkd-link.c.ORIG	2019-04-11 18:28:36.000000000 +0200
+++ b/src/network/networkd-link.c	2019-05-05 12:05:38.005897076 +0200
@@ -320,9 +320,11 @@
         disabled = !link_ipv6_enabled(link);
 
         r = sysctl_write_ip_property_boolean(AF_INET6, link->ifname, "disable_ipv6", disabled);
-        if (r < 0)
-                log_link_warning_errno(link, r, "Cannot %s IPv6 for interface %s: %m",
-                                       enable_disable(!disabled), link->ifname);
+        if (r < 0) {
+                if ( link->ifname )
+                  log_link_warning_errno(link, r, "Cannot %s IPv6 for interface %s: %m",
+                                         enable_disable(!disabled), link->ifname);
+        }
         else
                 log_link_info(link, "IPv6 successfully %sd", enable_disable(!disabled));