diff --git a/contrib/sim-rest-server.py b/contrib/sim-rest-server.py
index fc8afd94..0e44b23a 100755
--- a/contrib/sim-rest-server.py
+++ b/contrib/sim-rest-server.py
@@ -38,7 +38,7 @@ class ApduPrintTracer(ApduTracer):
         pass
 
 def connect_to_card(slot_nr:int):
-    tp = PcscSimLink(slot_nr, apdu_tracer=ApduPrintTracer())
+    tp = PcscSimLink(argparse.Namespace(pcsc_dev=slot_nr), apdu_tracer=ApduPrintTracer())
     tp.connect()
 
     scc = SimCardCommands(tp)
diff --git a/pySim/transport/__init__.py b/pySim/transport/__init__.py
index 2ffb9c35..e0e1e620 100644
--- a/pySim/transport/__init__.py
+++ b/pySim/transport/__init__.py
@@ -289,17 +289,15 @@ def init_reader(opts, **kwargs) -> LinkBase:
     """
     if opts.pcsc_dev is not None:
         from pySim.transport.pcsc import PcscSimLink
-        sl = PcscSimLink(opts.pcsc_dev, **kwargs)
+        sl = PcscSimLink(opts, **kwargs)
     elif opts.osmocon_sock is not None:
         from pySim.transport.calypso import CalypsoSimLink
-        sl = CalypsoSimLink(sock_path=opts.osmocon_sock, **kwargs)
+        sl = CalypsoSimLink(opts, **kwargs)
     elif opts.modem_dev is not None:
         from pySim.transport.modem_atcmd import ModemATCommandLink
-        sl = ModemATCommandLink(
-             device=opts.modem_dev, baudrate=opts.modem_baud, **kwargs)
+        sl = ModemATCommandLink(opts, **kwargs)
     else:  # Serial reader is default
         print("No reader/driver specified; falling back to default (Serial reader)")
         from pySim.transport.serial import SerialSimLink
-        sl = SerialSimLink(device=opts.device,
-                           baudrate=opts.baudrate, **kwargs)
+        sl = SerialSimLink(opts, **kwargs)
     return sl
diff --git a/pySim/transport/calypso.py b/pySim/transport/calypso.py
index 98330a97..01bbe232 100644
--- a/pySim/transport/calypso.py
+++ b/pySim/transport/calypso.py
@@ -77,7 +77,8 @@ class L1CTLMessageSIM(L1CTLMessage):
 class CalypsoSimLink(LinkBase):
     """Transport Link for Calypso based phones."""
 
-    def __init__(self, sock_path: str = "/tmp/osmocom_l2", **kwargs):
+    def __init__(self, opts: argparse.Namespace = argparse.Namespace(osmocon_sock="/tmp/osmocom_l2"), **kwargs):
+        sock_path = opts.osmocon_sock
         super().__init__(**kwargs)
         if os.environ.get('PYSIM_INTEGRATION_TEST') == "1":
             print("Using Calypso-based (OsmocomBB) reader interface")
diff --git a/pySim/transport/modem_atcmd.py b/pySim/transport/modem_atcmd.py
index 71f76e20..9a4f0a56 100644
--- a/pySim/transport/modem_atcmd.py
+++ b/pySim/transport/modem_atcmd.py
@@ -35,7 +35,10 @@ from pySim.exceptions import *
 class ModemATCommandLink(LinkBase):
     """Transport Link for 3GPP TS 27.007 compliant modems."""
 
-    def __init__(self, device: str = '/dev/ttyUSB0', baudrate: int = 115200, **kwargs):
+    def __init__(self, opts: argparse.Namespace = argparse.Namespace(modem_dev='/dev/ttyUSB0',
+                                                                     modem_baud=115200), **kwargs):
+        device = opts.modem_dev
+        baudrate = opts.modem_baud
         super().__init__(**kwargs)
         if os.environ.get('PYSIM_INTEGRATION_TEST') == "1":
             print("Using modem for Generic SIM Access (3GPP TS 27.007)")
diff --git a/pySim/transport/pcsc.py b/pySim/transport/pcsc.py
index 762908c6..6afcdac4 100644
--- a/pySim/transport/pcsc.py
+++ b/pySim/transport/pcsc.py
@@ -34,18 +34,18 @@ from pySim.utils import h2i, i2h, Hexstr, ResTuple
 class PcscSimLink(LinkBase):
     """ pySim: PCSC reader transport link."""
 
-    def __init__(self, reader_number: int = 0, **kwargs):
+    def __init__(self, opts: argparse.Namespace = argparse.Namespace(pcsc_dev=0), **kwargs):
         super().__init__(**kwargs)
         if os.environ.get('PYSIM_INTEGRATION_TEST') == "1":
             print("Using PC/SC reader interface")
         else:
-            print("Using PC/SC reader number %u" % reader_number)
+            print("Using PC/SC reader number %u" % opts.pcsc_dev)
         r = readers()
-        if reader_number >= len(r):
-            raise ReaderError('No reader found for number %d' % reader_number)
-        self._reader = r[reader_number]
+        if opts.pcsc_dev >= len(r):
+            raise ReaderError('No reader found for number %d' % opts.pcsc_dev)
+        self._reader = r[opts.pcsc_dev]
         self._con = self._reader.createConnection()
-        self._reader_number = reader_number
+        self._reader_number = opts.pcsc_dev
 
     def __del__(self):
         try:
diff --git a/pySim/transport/serial.py b/pySim/transport/serial.py
index ad800ede..e6803bef 100644
--- a/pySim/transport/serial.py
+++ b/pySim/transport/serial.py
@@ -30,24 +30,24 @@ from pySim.utils import h2b, b2h, Hexstr, ResTuple
 class SerialSimLink(LinkBase):
     """ pySim: Transport Link for serial (RS232) based readers included with simcard"""
 
-    def __init__(self, device: str = '/dev/ttyUSB0', baudrate: int = 9600, rst: str = '-rts',
+    def __init__(self, opts = argparse.Namespace(device='/dev/ttyUSB0', baudrate=9600), rst: str = '-rts',
                  debug: bool = False, **kwargs):
         super().__init__(**kwargs)
         if os.environ.get('PYSIM_INTEGRATION_TEST') == "1":
             print("Using serial reader interface")
         else:
-            print("Using serial reader interface at port %s" % device)
-        if not os.path.exists(device):
-            raise ValueError("device file %s does not exist -- abort" % device)
+            print("Using serial reader interface at port %s" % opts.device)
+        if not os.path.exists(opts.device):
+            raise ValueError("device file %s does not exist -- abort" % opts.device)
         self._sl = serial.Serial(
-            port=device,
+            port=opts.device,
             parity=serial.PARITY_EVEN,
             bytesize=serial.EIGHTBITS,
             stopbits=serial.STOPBITS_TWO,
             timeout=1,
             xonxoff=0,
             rtscts=0,
-            baudrate=baudrate,
+            baudrate=opts.baudrate,
         )
         self._rst_pin = rst
         self._debug = debug