diff --git a/src/modules/module-client-node/remote-node.c b/src/modules/module-client-node/remote-node.c
index f5d116f59..17c1c5780 100644
--- a/src/modules/module-client-node/remote-node.c
+++ b/src/modules/module-client-node/remote-node.c
@@ -889,8 +889,9 @@ static void clear_mix(struct node_data *data, struct mix *mix)
 {
 	pw_log_debug("port %p: mix clear %d.%d", mix->port, mix->port->port_id, mix->mix.id);
 
-	spa_node_port_set_io(mix->port->mix, mix->mix.port.direction,
-			mix->mix.port.port_id, SPA_IO_Buffers, NULL, 0);
+	if (mix->mix.id != SPA_ID_INVALID)
+		spa_node_port_set_io(mix->port->mix, mix->mix.port.direction,
+				mix->mix.port.port_id, SPA_IO_Buffers, NULL, 0);
 
 	spa_list_remove(&mix->link);