diff --git a/b2/_internal/_cli/obj_loads.py b/b2/_internal/_cli/obj_loads.py
index ea8f0b935..4a75af0a8 100644
--- a/b2/_internal/_cli/obj_loads.py
+++ b/b2/_internal/_cli/obj_loads.py
@@ -57,7 +57,13 @@ def describe_type(type_) -> str:
 def type_with_config(type_: type[T], config: pydantic.ConfigDict) -> type[T]:
     type_ = copy.copy(type_)
     if not hasattr(type_, '__config__'):
-        type_.__pydantic_config__ = config
+        try:
+            type_.__pydantic_config__ = config
+        except AttributeError:
+            # parametrized builtin generics (e.g. `list[LifecycleRule]`) are `types.GenericAlias` objects,
+            # which do not accept new attributes; use the type as is, `validated_loads` passes the config
+            # to `TypeAdapter` directly in that case
+            pass
     else:
         type_.__config__ = type_.__config__.copy()
         type_.__config__.update(config)
@@ -67,9 +73,13 @@ def type_with_config(type_: type[T], config: pydantic.ConfigDict) -> type[T]:
 def validated_loads(data: str, expected_type: type[T] | None = None) -> T:
     val = _UNDEF
     if expected_type is not None and pydantic is not None:
-        expected_type = type_with_config(expected_type, pydantic.ConfigDict(extra='allow'))
+        config = pydantic.ConfigDict(extra='allow')
+        expected_type = type_with_config(expected_type, config)
+        has_config = hasattr(expected_type, '__pydantic_config__') or hasattr(
+            expected_type, '__config__'
+        )
         try:
-            ta = TypeAdapter(expected_type)
+            ta = TypeAdapter(expected_type, config=None if has_config else config)
         except TypeError:
             # TypeError: unsupported operand type(s) for |: 'type' and 'NoneType'
             # This is thrown on python<3.10 even with eval_type_backport
diff --git a/changelog.d/+pydantic-generic-alias.fixed.md b/changelog.d/+pydantic-generic-alias.fixed.md
new file mode 100644
index 000000000..7bfa3199d
--- /dev/null
+++ b/changelog.d/+pydantic-generic-alias.fixed.md
@@ -0,0 +1 @@
+Fix `b2 bucket create` and `b2 bucket update` with the deprecated `--lifecycle-rules` option (and other JSON options typed as a parametrized list) failing with `AttributeError: 'types.GenericAlias' object has no attribute '__pydantic_config__'` when the `full` extra (pydantic) is installed.
diff --git a/test/unit/_cli/test_obj_loads.py b/test/unit/_cli/test_obj_loads.py
index f92101452..f0502df6c 100644
--- a/test/unit/_cli/test_obj_loads.py
+++ b/test/unit/_cli/test_obj_loads.py
@@ -66,3 +66,18 @@ def test_validated_loads__typed_dict_types_validation(typed_dict_cls):
     input_ = '{"a": "abc", "b": 2}'
     with pytest.raises(argparse.ArgumentTypeError):
         validated_loads(input_, typed_dict_cls)
+
+
+@pytest.mark.skipif(pydantic is None, reason='pydantic is not enabled')
+def test_validated_loads__parametrized_generic(typed_dict_cls):
+    # `list[...]` is a `types.GenericAlias`, which does not accept new attributes; extra keys must be kept
+    input_ = '[{"a": 1, "b": "2", "extra": null}]'
+    expected_val = [{'a': 1, 'b': '2', 'extra': None}]
+    assert validated_loads(input_, list[typed_dict_cls]) == expected_val
+
+
+@pytest.mark.skipif(pydantic is None, reason='pydantic is not enabled')
+def test_validated_loads__parametrized_generic_types_validation(typed_dict_cls):
+    input_ = '[{"a": "abc", "b": 2}]'
+    with pytest.raises(argparse.ArgumentTypeError):
+        validated_loads(input_, list[typed_dict_cls])