diff --git a/libagent/device/keepkey_defs.py b/libagent/device/keepkey_defs.py
index 5ecf127..9791ad0 100644
--- a/libagent/device/keepkey_defs.py
+++ b/libagent/device/keepkey_defs.py
@@ -5,5 +5,10 @@
 from keepkeylib.client import CallException, PinException
 from keepkeylib.client import KeepKeyClient as Client
 from keepkeylib.messages_pb2 import PassphraseAck, PinMatrixAck
-from keepkeylib.transport_hid import HidTransport as Transport
+from keepkeylib.transport_hid import HidTransport
 from keepkeylib.types_pb2 import IdentityType
+
+
+def enumerate_transports():
+    """Returns USB HID transports."""
+    return [HidTransport(p) for p in HidTransport.enumerate()]
diff --git a/libagent/device/trezor.py b/libagent/device/trezor.py
index 04db53a..c5a5906 100644
--- a/libagent/device/trezor.py
+++ b/libagent/device/trezor.py
@@ -115,14 +115,14 @@ class Trezor(interface.Device):
                                         current_version))
 
     def connect(self):
-        """Enumerate and connect to the first USB HID interface."""
-        transport = self._defs.TrezorDevice.enumerate()
-        if not transport:
+        """Enumerate and connect to the first available interface."""
+        transports = self._defs.enumerate_transports()
+        if not transports:
             raise interface.NotFoundError('{} not connected'.format(self))
 
-        log.debug('transports: %s', transport)
+        log.debug('transports: %s', transports)
         for _ in range(5):
-            connection = self._defs.Client(transport[0])
+            connection = self._defs.Client(transports[0])
             self._override_pin_handler(connection)
             self._override_passphrase_handler(connection)
             self._verify_version(connection)
diff --git a/libagent/device/trezor_defs.py b/libagent/device/trezor_defs.py
index 5804e4b..a4daf81 100644
--- a/libagent/device/trezor_defs.py
+++ b/libagent/device/trezor_defs.py
@@ -6,3 +6,8 @@ from trezorlib.client import CallException, PinException
 from trezorlib.client import TrezorClient as Client
 from trezorlib.messages import IdentityType, PassphraseAck, PinMatrixAck
 from trezorlib.device import TrezorDevice
+
+
+def enumerate_transports():
+    """Returns all available transports."""
+    return TrezorDevice.enumerate()