diff --git a/src/hardware/agilent-dmm/api.c b/src/hardware/agilent-dmm/api.c
index c89d18ed..fb40818f 100644
--- a/src/hardware/agilent-dmm/api.c
+++ b/src/hardware/agilent-dmm/api.c
@@ -112,7 +112,7 @@ static GSList *scan(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);