diff --git a/src/mesh/mesh_network.c b/src/mesh/mesh_network.c
index d5300170b..025107c69 100644
--- a/src/mesh/mesh_network.c
+++ b/src/mesh/mesh_network.c
@@ -988,8 +988,7 @@ void mesh_network_send_pdu(mesh_network_pdu_t * network_pdu){
     printf("^^ into network_pdus_queued\n");
 #endif
 
-    uint8_t net_mic_len = network_pdu->data[1] & 0x80 ? 8 : 4;
-    btstack_assert((network_pdu->len + net_mic_len) <= 29);
+    btstack_assert((network_pdu->len + (network_pdu->data[1] & 0x80 ? 8 : 4)) <= 29);
     btstack_assert(network_pdu->len >= 9);
 
     // setup callback
diff --git a/src/mesh/mesh_upper_transport.c b/src/mesh/mesh_upper_transport.c
index 7d7f6614f..10aa83e30 100644
--- a/src/mesh/mesh_upper_transport.c
+++ b/src/mesh/mesh_upper_transport.c
@@ -1008,9 +1008,9 @@ void mesh_upper_transport_init(){
 
 void mesh_upper_transport_send_access_pdu(mesh_pdu_t *pdu){
     if (pdu->pdu_type == MESH_PDU_TYPE_NETWORK){
-        mesh_network_pdu_t * network_pdu = (mesh_network_pdu_t *) pdu;
-        btstack_assert(network_pdu->len >= 9);
+        btstack_assert(mesh_network_pdu_len((mesh_network_pdu_t *) pdu) >= 9);
     }
+
     btstack_linked_list_add_tail(&upper_transport_outgoing, (btstack_linked_item_t*) pdu);
     mesh_upper_transport_run();
 }