diff --git a/src/core/ipv4/etharp.c b/src/core/ipv4/etharp.c
index 3092dc94..520abb9e 100644
--- a/src/core/ipv4/etharp.c
+++ b/src/core/ipv4/etharp.c
@@ -1015,7 +1015,7 @@ etharp_query(struct netif *netif, const ip4_addr_t *ipaddr, struct pbuf *q)
      * new PBUF_RAM. See the definition of PBUF_NEEDS_COPY for details. */
     p = q;
     while (p) {
-      LWIP_ASSERT("no packet queues allowed!", (p->len != p->tot_len) || (p->next == NULL));
+      LWIP_ASSERT("no packet queues allowed!", (p->len == p->tot_len) && (p->next == NULL));
       if (PBUF_NEEDS_COPY(p)) {
         copy_needed = 1;
         break;