diff --git a/pySim/transport/__init__.py b/pySim/transport/__init__.py
index a16fdb3e..c8079f66 100644
--- a/pySim/transport/__init__.py
+++ b/pySim/transport/__init__.py
@@ -10,12 +10,12 @@ from construct import Construct
 
 from pySim.exceptions import *
 from pySim.construct import filter_dict
-from pySim.utils import sw_match, b2h, h2b, i2h, Hexstr, SwHexstr, SwMatchstr
+from pySim.utils import sw_match, b2h, h2b, i2h, Hexstr, SwHexstr, SwMatchstr, ResTuple
 from pySim.cat import ProactiveCommand, CommandDetails, DeviceIdentities, Result
 
 #
 # Copyright (C) 2009-2010  Sylvain Munaut <tnt@246tNt.com>
-# Copyright (C) 2021-2022 Harald Welte <laforge@osmocom.org>
+# Copyright (C) 2021-2023 Harald Welte <laforge@osmocom.org>
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -68,7 +68,7 @@ class LinkBase(abc.ABC):
         self.proactive_handler = proactive_handler
 
     @abc.abstractmethod
-    def _send_apdu_raw(self, pdu: Hexstr) -> Tuple[Hexstr, Hexstr]:
+    def _send_apdu_raw(self, pdu: Hexstr) -> ResTuple:
         """Implementation specific method for sending the PDU."""
 
     def set_sw_interpreter(self, interp):
@@ -99,7 +99,7 @@ class LinkBase(abc.ABC):
         """Resets the card (power down/up)
         """
 
-    def send_apdu_raw(self, pdu: Hexstr) -> Tuple[Hexstr, SwHexstr]:
+    def send_apdu_raw(self, pdu: Hexstr) -> ResTuple:
         """Sends an APDU with minimal processing
 
         Args:
@@ -116,7 +116,7 @@ class LinkBase(abc.ABC):
             self.apdu_tracer.trace_response(pdu, sw, data)
         return (data, sw)
 
-    def send_apdu(self, pdu: Hexstr) -> Tuple[Hexstr, SwHexstr]:
+    def send_apdu(self, pdu: Hexstr) -> ResTuple:
         """Sends an APDU and auto fetch response data
 
         Args:
@@ -145,7 +145,7 @@ class LinkBase(abc.ABC):
 
         return data, sw
 
-    def send_apdu_checksw(self, pdu: Hexstr, sw: SwMatchstr = "9000") -> Tuple[Hexstr, SwHexstr]:
+    def send_apdu_checksw(self, pdu: Hexstr, sw: SwMatchstr = "9000") -> ResTuple:
         """Sends an APDU and check returned SW
 
         Args:
diff --git a/pySim/transport/calypso.py b/pySim/transport/calypso.py
index 4244b230..34fc6465 100644
--- a/pySim/transport/calypso.py
+++ b/pySim/transport/calypso.py
@@ -21,11 +21,11 @@ import struct
 import socket
 import os
 
-from typing import Optional, Tuple
+from typing import Optional
 
 from pySim.transport import LinkBase
 from pySim.exceptions import *
-from pySim.utils import h2b, b2h, Hexstr, SwHexstr
+from pySim.utils import h2b, b2h, Hexstr, ResTuple
 
 
 class L1CTLMessage:
@@ -123,7 +123,7 @@ class CalypsoSimLink(LinkBase):
     def wait_for_card(self, timeout: Optional[int] = None, newcardonly: bool = False):
         pass  # Nothing to do really ...
 
-    def _send_apdu_raw(self, pdu: Hexstr) -> Tuple[Hexstr, SwHexstr]:
+    def _send_apdu_raw(self, pdu: Hexstr) -> ResTuple:
 
         # Request FULL reset
         req_msg = L1CTLMessageSIM(h2b(pdu))
diff --git a/pySim/transport/modem_atcmd.py b/pySim/transport/modem_atcmd.py
index c6f6c57e..e99762dd 100644
--- a/pySim/transport/modem_atcmd.py
+++ b/pySim/transport/modem_atcmd.py
@@ -20,9 +20,9 @@ import logging as log
 import serial
 import time
 import re
-from typing import Optional, Tuple
+from typing import Optional
 
-from pySim.utils import Hexstr, SwHexstr
+from pySim.utils import Hexstr, ResTuple
 from pySim.transport import LinkBase
 from pySim.exceptions import *
 
@@ -141,7 +141,7 @@ class ModemATCommandLink(LinkBase):
     def wait_for_card(self, timeout: Optional[int] = None, newcardonly: bool = False):
         pass  # Nothing to do really ...
 
-    def _send_apdu_raw(self, pdu: Hexstr) -> Tuple[Hexstr, SwHexstr]:
+    def _send_apdu_raw(self, pdu: Hexstr) -> ResTuple:
         # Make sure pdu has upper case hex digits [A-F]
         pdu = pdu.upper()
 
diff --git a/pySim/transport/pcsc.py b/pySim/transport/pcsc.py
index f0b3e67a..a01917f4 100644
--- a/pySim/transport/pcsc.py
+++ b/pySim/transport/pcsc.py
@@ -17,7 +17,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #
 
-from typing import Optional, Tuple
+from typing import Optional
 
 from smartcard.CardConnection import CardConnection
 from smartcard.CardRequest import CardRequest
@@ -26,7 +26,7 @@ from smartcard.System import readers
 
 from pySim.exceptions import NoCardError, ProtocolError, ReaderError
 from pySim.transport import LinkBase
-from pySim.utils import h2i, i2h, Hexstr, SwHexstr
+from pySim.utils import h2i, i2h, Hexstr, ResTuple
 
 
 class PcscSimLink(LinkBase):
@@ -81,7 +81,7 @@ class PcscSimLink(LinkBase):
         self.connect()
         return 1
 
-    def _send_apdu_raw(self, pdu: Hexstr) -> Tuple[Hexstr, SwHexstr]:
+    def _send_apdu_raw(self, pdu: Hexstr) -> ResTuple:
 
         apdu = h2i(pdu)
 
diff --git a/pySim/transport/serial.py b/pySim/transport/serial.py
index daf2eb82..998d1d89 100644
--- a/pySim/transport/serial.py
+++ b/pySim/transport/serial.py
@@ -19,11 +19,11 @@
 import serial
 import time
 import os.path
-from typing import Optional, Tuple
+from typing import Optional
 
 from pySim.exceptions import NoCardError, ProtocolError
 from pySim.transport import LinkBase
-from pySim.utils import h2b, b2h, Hexstr, SwHexstr
+from pySim.utils import h2b, b2h, Hexstr, ResTuple
 
 
 class SerialSimLink(LinkBase):
@@ -185,7 +185,7 @@ class SerialSimLink(LinkBase):
     def _rx_byte(self):
         return self._sl.read()
 
-    def _send_apdu_raw(self, pdu: Hexstr) -> Tuple[Hexstr, SwHexstr]:
+    def _send_apdu_raw(self, pdu: Hexstr) -> ResTuple:
 
         pdu = h2b(pdu)
         data_len = pdu[4]  # P3