diff --git a/bumble/transport/__init__.py b/bumble/transport/__init__.py
index 4822dfe1..065e6964 100644
--- a/bumble/transport/__init__.py
+++ b/bumble/transport/__init__.py
@@ -111,75 +111,75 @@ async def _open_transport(scheme: str, spec: Optional[str]) -> Transport:
     if scheme == 'serial' and spec:
         from .serial import open_serial_transport
 
-        return await open_serial_transport(spec[0])
+        return await open_serial_transport(spec)
 
     if scheme == 'udp' and spec:
         from .udp import open_udp_transport
 
-        return await open_udp_transport(spec[0])
+        return await open_udp_transport(spec)
 
     if scheme == 'tcp-client' and spec:
         from .tcp_client import open_tcp_client_transport
 
-        return await open_tcp_client_transport(spec[0])
+        return await open_tcp_client_transport(spec)
 
     if scheme == 'tcp-server' and spec:
         from .tcp_server import open_tcp_server_transport
 
-        return await open_tcp_server_transport(spec[0])
+        return await open_tcp_server_transport(spec)
 
     if scheme == 'ws-client' and spec:
         from .ws_client import open_ws_client_transport
 
-        return await open_ws_client_transport(spec[0])
+        return await open_ws_client_transport(spec)
 
     if scheme == 'ws-server' and spec:
         from .ws_server import open_ws_server_transport
 
-        return await open_ws_server_transport(spec[0])
+        return await open_ws_server_transport(spec)
 
     if scheme == 'pty':
         from .pty import open_pty_transport
 
-        return await open_pty_transport(spec[0] if spec else None)
+        return await open_pty_transport(spec)
 
     if scheme == 'file':
         from .file import open_file_transport
 
         assert spec is not None
-        return await open_file_transport(spec[0])
+        return await open_file_transport(spec)
 
     if scheme == 'vhci':
         from .vhci import open_vhci_transport
 
-        return await open_vhci_transport(spec[0] if spec else None)
+        return await open_vhci_transport(spec)
 
     if scheme == 'hci-socket':
         from .hci_socket import open_hci_socket_transport
 
-        return await open_hci_socket_transport(spec[0] if spec else None)
+        return await open_hci_socket_transport(spec)
 
     if scheme == 'usb':
         from .usb import open_usb_transport
 
-        assert spec is not None
-        return await open_usb_transport(spec[0])
+        assert spec
+        return await open_usb_transport(spec)
 
     if scheme == 'pyusb':
         from .pyusb import open_pyusb_transport
 
-        assert spec is not None
-        return await open_pyusb_transport(spec[0])
+        assert spec
+        return await open_pyusb_transport(spec)
 
     if scheme == 'android-emulator':
         from .android_emulator import open_android_emulator_transport
 
-        return await open_android_emulator_transport(spec[0] if spec else None)
+        return await open_android_emulator_transport(spec)
 
     if scheme == 'android-netsim':
         from .android_netsim import open_android_netsim_transport
 
-        return await open_android_netsim_transport(spec[0] if spec else None)
+        return await open_android_netsim_transport(spec)
 
     raise ValueError('unknown transport scheme')
 
diff --git a/bumble/transport/android_emulator.py b/bumble/transport/android_emulator.py
index 8d19a9e2..9cd7ec21 100644
--- a/bumble/transport/android_emulator.py
+++ b/bumble/transport/android_emulator.py
@@ -69,7 +69,7 @@ async def open_android_emulator_transport(spec: Optional[str]) -> Transport:
     mode = 'host'
     server_host = 'localhost'
     server_port = '8554'
-    if spec is not None:
+    if spec:
         params = spec.split(',')
         for param in params:
             if param.startswith('mode='):
diff --git a/bumble/transport/hci_socket.py b/bumble/transport/hci_socket.py
index df9e885a..41250433 100644
--- a/bumble/transport/hci_socket.py
+++ b/bumble/transport/hci_socket.py
@@ -59,10 +59,7 @@ async def open_hci_socket_transport(spec: Optional[str]) -> Transport:
         ) from error
 
     # Compute the adapter index
-    if spec is None:
-        adapter_index = 0
-    else:
-        adapter_index = int(spec)
+    adapter_index = int(spec) if spec else 0
 
     # Bind the socket
     # NOTE: since Python doesn't support binding with the required address format (yet),