diff --git a/core/net/mac/tsch/tsch.c b/core/net/mac/tsch/tsch.c
index b97e1d634..e03d34a50 100644
--- a/core/net/mac/tsch/tsch.c
+++ b/core/net/mac/tsch/tsch.c
@@ -928,7 +928,10 @@ send_packet(mac_callback_t sent, void *ptr)
     /* Enqueue packet */
     p = tsch_queue_add_packet(addr, sent, ptr);
     if(p == NULL) {
-      PRINTF("TSCH:! can't send packet !tsch_queue_add_packet\n");
+      PRINTF("TSCH:! can't send packet to %u with seqno %u, queue %u %u\n",
+          TSCH_LOG_ID_FROM_LINKADDR(addr), tsch_packet_seqno,
+          packet_count_before,
+          tsch_queue_packet_count(addr));
       ret = MAC_TX_ERR;
     } else {
       p->header_len = hdr_len;