diff --git a/drivers/net/mlx5/mlx5_rxtx.h b/drivers/net/mlx5/mlx5_rxtx.h
index 56da93480f..b40177d429 100644
--- a/drivers/net/mlx5/mlx5_rxtx.h
+++ b/drivers/net/mlx5/mlx5_rxtx.h
@@ -576,6 +576,11 @@ mlx5_tx_mb2mr(struct mlx5_txq_data *txq, struct rte_mbuf *mb)
 	if (mr) {
 		rte_atomic32_inc(&mr->refcnt);
 		return mr->lkey;
+	} else {
+		struct rte_mempool *mp = mlx5_tx_mb2mp(mb);
+
+		WARN("Failed to register mempool 0x%p(%s)",
+		      (void *)mp, mp->name);
 	}
 	return (uint32_t)-1;
 }