diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c
index 7713946e6ded..4e1a061fcc14 100644
--- a/drivers/ntb/ntb_transport.c
+++ b/drivers/ntb/ntb_transport.c
@@ -2199,7 +2199,7 @@ unsigned int ntb_transport_tx_free_entry(struct ntb_transport_qp *qp)
 	unsigned int head = qp->tx_index;
 	unsigned int tail = qp->remote_rx_info->entry;
 
-	return tail > head ? tail - head : qp->tx_max_entry + tail - head;
+	return tail >= head ? tail - head : qp->tx_max_entry + tail - head;
 }
 EXPORT_SYMBOL_GPL(ntb_transport_tx_free_entry);