diff --git a/core/net/uip.h b/core/net/uip.h
index f04ebd0d9..449b08443 100644
--- a/core/net/uip.h
+++ b/core/net/uip.h
@@ -1935,7 +1935,8 @@ CCIF extern uip_lladdr_t uip_lladdr;
    (((a)->u16[4]) == 0) &&                       \
    (((a)->u16[5]) == 0) &&                       \
    (((a)->u16[6]) == 0) &&                       \
-   (((a)->u16[7]) == 1))
+   (((a)->u8[14]) == 0) &&                       \
+   (((a)->u8[15]) == 0x01))
 /**
  * \brief Is IPv6 address a the unspecified address
  * a is of type uip_ipaddr_t