diff --git a/speculos/mcu/seproxyhal.py b/speculos/mcu/seproxyhal.py
index 37f1834e..8d3b6147 100644
--- a/speculos/mcu/seproxyhal.py
+++ b/speculos/mcu/seproxyhal.py
@@ -275,7 +275,7 @@ def __init__(self,
                                                    self.socket_helper.wait_until_tick_is_processed)
         self.time_ticker_thread.start()
 
-        usb_transport = transport if transport in ['hid', 'u2f'] else 'hid'
+        usb_transport = transport if transport.lower() in ['hid', 'u2f'] else 'hid'
         self.usb = usb.USB(self.socket_helper.queue_packet, transport=usb_transport)
 
         self.nfc = nfc.NFC(self.socket_helper.queue_packet)