diff --git a/src/hardware/norma-dmm/api.c b/src/hardware/norma-dmm/api.c
index deefceae..e1929bd7 100644
--- a/src/hardware/norma-dmm/api.c
+++ b/src/hardware/norma-dmm/api.c
@@ -115,7 +115,7 @@ static GSList *do_scan(struct sr_dev_driver* drv, GSList *options)
 	if (!(serial = sr_serial_dev_inst_new(conn, serialcomm)))
 		return NULL;
 
-	if (serial_open(serial, SERIAL_RDWR | SERIAL_NONBLOCK) != SR_OK)
+	if (serial_open(serial, SERIAL_RDWR) != SR_OK)
 		return NULL;
 
 	serial_flush(serial);