diff --git a/src/std.c b/src/std.c
index 910e8847..7d78578d 100644
--- a/src/std.c
+++ b/src/std.c
@@ -115,7 +115,7 @@ SR_PRIV int std_session_send_df_header(const struct sr_dev_inst *sdi,
  *
  * This function can be used to implement the dev_open() driver API
  * callback in drivers that use a serial port. The port is opened
- * with the SERIAL_RDWR and SERIAL_NONBLOCK flags.
+ * with the SERIAL_RDWR flag.
  *
  * If the open succeeded, the status field of the given sdi is set
  * to SR_ST_ACTIVE.
@@ -128,7 +128,7 @@ SR_PRIV int std_serial_dev_open(struct sr_dev_inst *sdi)
 	struct sr_serial_dev_inst *serial;
 
 	serial = sdi->conn;
-	if (serial_open(serial, SERIAL_RDWR | SERIAL_NONBLOCK) != SR_OK)
+	if (serial_open(serial, SERIAL_RDWR) != SR_OK)
 		return SR_ERR;
 
 	sdi->status = SR_ST_ACTIVE;