diff --git a/sys/include/net/gnrc/ipv6/nib/nc.h b/sys/include/net/gnrc/ipv6/nib/nc.h
index a46ae589d2..3141422983 100644
--- a/sys/include/net/gnrc/ipv6/nib/nc.h
+++ b/sys/include/net/gnrc/ipv6/nib/nc.h
@@ -207,7 +207,7 @@ static inline unsigned gnrc_ipv6_nib_nc_get_ar_state(const gnrc_ipv6_nib_nc_t *e
 /**
  * @brief   Adds an unmanaged neighbor entry to NIB
  *
- * @pre `(ipv6 != NULL) && (l2addr != NULL)`
+ * @pre `ipv6 != NULL`
  * @pre `l2addr_len <= GNRC_IPV6_NIB_L2ADDR_MAX_LEN`
  * @pre `(iface > KERNEL_PID_UNDEF) && (iface <= KERNEL_PID_LAST)`
  *
diff --git a/sys/net/gnrc/network_layer/ipv6/nib/nib_nc.c b/sys/net/gnrc/network_layer/ipv6/nib/nib_nc.c
index 6c97467a4f..f5537d938d 100644
--- a/sys/net/gnrc/network_layer/ipv6/nib/nib_nc.c
+++ b/sys/net/gnrc/network_layer/ipv6/nib/nib_nc.c
@@ -29,7 +29,7 @@ int gnrc_ipv6_nib_nc_set(const ipv6_addr_t *ipv6, unsigned iface,
 {
     _nib_onl_entry_t *node;
 
-    assert((ipv6 != NULL) && (l2addr != NULL));
+    assert(ipv6 != NULL);
     assert(l2addr_len <= GNRC_IPV6_NIB_L2ADDR_MAX_LEN);
     assert((iface > KERNEL_PID_UNDEF) && (iface <= KERNEL_PID_LAST));
     mutex_lock(&_nib_mutex);
@@ -39,7 +39,9 @@ int gnrc_ipv6_nib_nc_set(const ipv6_addr_t *ipv6, unsigned iface,
         return -ENOMEM;
     }
 #if GNRC_IPV6_NIB_CONF_ARSM
-    memcpy(node->l2addr, l2addr, l2addr_len);
+    if ((l2addr != NULL) && (l2addr_len > 0)) {
+        memcpy(node->l2addr, l2addr, l2addr_len);
+    }
     node->l2addr_len = l2addr_len;
 #else
     (void)l2addr;