diff --git a/pySim/global_platform/__init__.py b/pySim/global_platform/__init__.py
index 6793f711..25b0d02f 100644
--- a/pySim/global_platform/__init__.py
+++ b/pySim/global_platform/__init__.py
@@ -501,9 +501,9 @@ class ADF_SD(CardADF):
             return data
 
         put_key_parser = argparse.ArgumentParser()
-        put_key_parser.add_argument('--old-key-version-nr', type=auto_int, default=0, help='Old Key Version Number')
-        put_key_parser.add_argument('--key-version-nr', type=auto_int, required=True, help='Key Version Number')
-        put_key_parser.add_argument('--key-id', type=auto_int, required=True, help='Key Identifier (base)')
+        put_key_parser.add_argument('--old-key-version-nr', type=auto_uint8, default=0, help='Old Key Version Number')
+        put_key_parser.add_argument('--key-version-nr', type=auto_uint8, required=True, help='Key Version Number')
+        put_key_parser.add_argument('--key-id', type=auto_uint7, required=True, help='Key Identifier (base)')
         put_key_parser.add_argument('--key-type', choices=KeyType.ksymapping.values(), action='append', required=True, help='Key Type')
         put_key_parser.add_argument('--key-data', type=is_hexstr, action='append', required=True, help='Key Data Block')
         put_key_parser.add_argument('--key-check', type=is_hexstr, action='append', help='Key Check Value')
diff --git a/pySim/utils.py b/pySim/utils.py
index cf95dab6..a31fbe0e 100644
--- a/pySim/utils.py
+++ b/pySim/utils.py
@@ -7,6 +7,7 @@ import json
 import abc
 import string
 import datetime
+import argparse
 from io import BytesIO
 from typing import Optional, List, Dict, Any, Tuple, NewType
 
@@ -913,6 +914,18 @@ def auto_int(x):
     """Helper function for argparse to accept hexadecimal integers."""
     return int(x, 0)
 
+def _auto_uint(x, max_val: int):
+    """Helper function for argparse to accept hexadecimal or decimal integers."""
+    ret = int(x, 0)
+    if ret < 0 or ret > max_val:
+        raise argparse.ArgumentTypeError('Number exceeds permited value range (0, %u)' %  max_val)
+    return ret
+
+def auto_uint7(x):
+    return _auto_uint(x, 127)
+
+def auto_uint8(x):
+    return _auto_uint(x, 255)
 
 def expand_hex(hexstring, length):
     """Expand a given hexstring to a specified length by replacing "." or ".."