diff --git a/developerbox_spi.c b/developerbox_spi.c
index e186240..c327043 100644
--- a/developerbox_spi.c
+++ b/developerbox_spi.c
@@ -155,7 +155,7 @@
 	if (register_shutdown(developerbox_spi_shutdown, NULL))
 		goto err_exit;
 
-	if (register_spi_bitbang_master(&bitbang_spi_master_cp210x))
+	if (register_spi_bitbang_master(&bitbang_spi_master_cp210x, NULL))
 		goto err_exit;
 
 	return 0;