diff --git a/sys/net/gnrc/network_layer/ndp/gnrc_ndp.c b/sys/net/gnrc/network_layer/ndp/gnrc_ndp.c
index 03d5bc7e1e..4136b39431 100644
--- a/sys/net/gnrc/network_layer/ndp/gnrc_ndp.c
+++ b/sys/net/gnrc/network_layer/ndp/gnrc_ndp.c
@@ -57,13 +57,17 @@ static void _stale_nc(kernel_pid_t iface, ipv6_addr_t *ipaddr, uint8_t *l2addr,
 #ifdef MODULE_GNRC_SIXLOWPAN_ND_ROUTER
             /* tentative type see https://tools.ietf.org/html/rfc6775#section-6.3 */
             gnrc_ipv6_netif_t *ipv6_iface = gnrc_ipv6_netif_get(iface);
-            if (ipv6_iface->flags & GNRC_IPV6_NETIF_FLAGS_ROUTER) {
+            if ((ipv6_iface->flags & GNRC_IPV6_NETIF_FLAGS_SIXLOWPAN) &&
+                (ipv6_iface->flags & GNRC_IPV6_NETIF_FLAGS_ROUTER)) {
                 timex_t t = { GNRC_SIXLOWPAN_ND_TENTATIVE_NCE_LIFETIME, 0 };
-                gnrc_ipv6_nc_add(iface, ipaddr, l2addr, (uint16_t)l2addr_len,
-                                 GNRC_IPV6_NC_STATE_STALE | GNRC_IPV6_NC_TYPE_TENTATIVE);
-                vtimer_remove(&nc_entry->type_timeout);
-                vtimer_set_msg(&nc_entry->type_timeout, t, gnrc_ipv6_pid,
-                               GNRC_SIXLOWPAN_ND_MSG_AR_TIMEOUT, nc_entry);
+                if ((nc_entry = gnrc_ipv6_nc_add(iface, ipaddr, l2addr,
+                                                 (uint16_t)l2addr_len,
+                                                 GNRC_IPV6_NC_STATE_STALE |
+                                                 GNRC_IPV6_NC_TYPE_TENTATIVE)) != NULL) {
+                    vtimer_remove(&nc_entry->type_timeout);
+                    vtimer_set_msg(&nc_entry->type_timeout, t, gnrc_ipv6_pid,
+                                   GNRC_SIXLOWPAN_ND_MSG_AR_TIMEOUT, nc_entry);
+                }
                 return;
             }
 #endif