diff --git a/src/hardware/serial-dmm/api.c b/src/hardware/serial-dmm/api.c
index f423f474..47811001 100644
--- a/src/hardware/serial-dmm/api.c
+++ b/src/hardware/serial-dmm/api.c
@@ -353,7 +353,7 @@ static GSList *sdmm_scan(const char *conn, const char *serialcomm, int dmm)
 	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;
 
 	sr_info("Probing serial port %s.", conn);