diff --git a/sys/net/gnrc/network_layer/ipv6/nib/_nib-6ln.h b/sys/net/gnrc/network_layer/ipv6/nib/_nib-6ln.h
index 489450ba8b..dca4eee612 100644
--- a/sys/net/gnrc/network_layer/ipv6/nib/_nib-6ln.h
+++ b/sys/net/gnrc/network_layer/ipv6/nib/_nib-6ln.h
@@ -34,7 +34,6 @@
 extern "C" {
 #endif
 
-#if IS_ACTIVE(CONFIG_GNRC_IPV6_NIB_6LN) || defined(DOXYGEN)
 /**
  * @brief   Additional (local) status to ARO status values for tentative
  *          addresses
@@ -57,6 +56,7 @@ extern "C" {
  */
 #define _ADDR_REG_STATUS_UNAVAIL        (255)
 
+#if IS_ACTIVE(CONFIG_GNRC_IPV6_NIB_6LN) || defined(DOXYGEN)
 /**
  * @brief   Resolves address statically from destination address using reverse
  *          translation of the IID
diff --git a/sys/net/gnrc/network_layer/ipv6/nib/_nib-arsm.c b/sys/net/gnrc/network_layer/ipv6/nib/_nib-arsm.c
index 3687e394d0..e3848c8c13 100644
--- a/sys/net/gnrc/network_layer/ipv6/nib/_nib-arsm.c
+++ b/sys/net/gnrc/network_layer/ipv6/nib/_nib-arsm.c
@@ -233,7 +233,19 @@ void _handle_snd_ns(_nib_onl_entry_t *nbr)
             }
             /* intentionally falls through */
         case GNRC_IPV6_NIB_NC_INFO_NUD_STATE_UNREACHABLE:
-            _probe_nbr(nbr, false);
+            if (!IS_ACTIVE(CONFIG_GNRC_IPV6_NIB_6LR) ||
+                /* if neighbor is a 6LoWPAN node (i.e. address registartion
+                 * state is non-garbage-collectible), only probe if it is a
+                 * router (where the solicited-nodes multicast address MUST
+                 * be set; only MAY otherwise).
+                 * See:
+                 * - https://tools.ietf.org/html/rfc6775#section-5.2
+                 * - https://tools.ietf.org/html/rfc6775#section-6.5.5
+                 */
+                (_get_ar_state(nbr) == GNRC_IPV6_NIB_NC_INFO_AR_STATE_GC) ||
+                (nbr->info & GNRC_IPV6_NIB_NC_INFO_IS_ROUTER)) {
+                _probe_nbr(nbr, false);
+            }
             break;
         default:
             break;