diff --git a/src/humanize/__init__.py b/src/humanize/__init__.py
index 4f54bc4..f9967ed 100644
--- a/src/humanize/__init__.py
+++ b/src/humanize/__init__.py
@@ -32,7 +32,10 @@
     precisedelta,
 )
 
-from ._version import __version__
+try:
+    from ._version import __version__
+except ImportError:
+    __version__ = "4.12.2.dev0"
 
 __all__ = [
     "__version__",
diff --git a/src/humanize/lists.py b/src/humanize/lists.py
index 525f0e3..7381aa7 100644
--- a/src/humanize/lists.py
+++ b/src/humanize/lists.py
@@ -4,35 +4,43 @@
 
 TYPE_CHECKING = False
 if TYPE_CHECKING:
+    from collections.abc import Iterable
     from typing import Any
 
 __all__ = ["natural_list"]
 
 
-def natural_list(items: list[Any]) -> str:
+def natural_list(items: Iterable[Any], oxford_comma: bool = False) -> str:
     """Natural list.
 
-    Convert a list of items into a human-readable string with commas and 'and'.
+    Convert a list or iterable of items into a human-readable string with
+    commas and 'and'.
 
     Examples:
         >>> natural_list(["one", "two", "three"])
         'one, two and three'
+        >>> natural_list(["one", "two", "three"], oxford_comma=True)
+        'one, two, and three'
         >>> natural_list(["one", "two"])
         'one and two'
         >>> natural_list(["one"])
         'one'
 
     Args:
-        items (list): An iterable of items.
+        items (iterable): An iterable of items.
+        oxford_comma (bool): If True, includes an Oxford comma before 'and'
+            for 3+ items.
 
     Returns:
         str: A string with commas and 'and' in the right places.
     """
-    if not items:
+    item_list = [str(item) for item in items]
+    if not item_list:
         return ""
-    if len(items) == 1:
-        return str(items[0])
-    elif len(items) == 2:
-        return f"{str(items[0])} and {str(items[1])}"
+    if len(item_list) == 1:
+        return item_list[0]
+    elif len(item_list) == 2:
+        return f"{item_list[0]} and {item_list[1]}"
     else:
-        return ", ".join([str(item) for item in items[:-1]]) + f" and {str(items[-1])}"
+        sep = ", and " if oxford_comma else " and "
+        return ", ".join(item_list[:-1]) + f"{sep}{item_list[-1]}"
diff --git a/src/humanize/number.py b/src/humanize/number.py
index 2fb22c6..593b408 100644
--- a/src/humanize/number.py
+++ b/src/humanize/number.py
@@ -109,7 +109,8 @@ def ordinal(value: NumberOrString, gender: str = "male") -> str:
     except (TypeError, ValueError):
         return str(value)
     gender = "male" if gender == "male" else "female"
-    digit = 0 if value % 100 in (11, 12, 13) else value % 10
+    abs_value = abs(value)
+    digit = 0 if abs_value % 100 in (11, 12, 13) else abs_value % 10
     return f"{value}{P_(f'{digit} ({gender})', _ORDINAL_SUFFIXES[digit])}"
 
 
diff --git a/tests/test_benchmarks.py b/tests/test_benchmarks.py
index c200dd0..a85127f 100644
--- a/tests/test_benchmarks.py
+++ b/tests/test_benchmarks.py
@@ -6,6 +6,8 @@
 
 import pytest
 
+pytest.importorskip("pytest_codspeed")
+
 import humanize
 
 TYPE_CHECKING = False
diff --git a/tests/test_i18n.py b/tests/test_i18n.py
index 6ea61a2..63c4380 100644
--- a/tests/test_i18n.py
+++ b/tests/test_i18n.py
@@ -6,10 +6,12 @@
 import importlib
 
 import pytest
-from freezegun import freeze_time
 
 import humanize
 
+freezegun = pytest.importorskip("freezegun")
+freeze_time = freezegun.freeze_time
+
 with freeze_time("2020-02-02"):
     NOW = dt.datetime.now(tz=dt.timezone.utc)
 
diff --git a/tests/test_lists.py b/tests/test_lists.py
index cc514f3..bbd4bf6 100644
--- a/tests/test_lists.py
+++ b/tests/test_lists.py
@@ -16,9 +16,20 @@
         ([[""]], ""),
         ([[1, 2, 3]], "1, 2 and 3"),
         ([[1, "two"]], "1 and two"),
+        ([("a", "b", "c")], "a, b and c"),
     ],
 )
 def test_natural_list(
     test_args: list[str] | list[int] | list[str | int], expected: str
 ) -> None:
     assert humanize.natural_list(*test_args) == expected
+
+
+def test_natural_list_generator_and_oxford_comma() -> None:
+    gen = (x for x in ["alpha", "beta", "gamma"])
+    assert humanize.natural_list(gen) == "alpha, beta and gamma"
+    assert (
+        humanize.natural_list(["one", "two", "three"], oxford_comma=True)
+        == "one, two, and three"
+    )
+    assert humanize.natural_list(["one", "two"], oxford_comma=True) == "one and two"
diff --git a/tests/test_number.py b/tests/test_number.py
index 78639c3..b2c3a0c 100644
--- a/tests/test_number.py
+++ b/tests/test_number.py
@@ -25,6 +25,12 @@
         ("102", "102nd"),
         ("103", "103rd"),
         ("111", "111th"),
+        ("-1", "-1st"),
+        ("-2", "-2nd"),
+        ("-3", "-3rd"),
+        ("-11", "-11th"),
+        ("-21", "-21st"),
+        ("-22", "-22nd"),
         ("something else", "something else"),
         (None, "None"),
         (math.nan, "NaN"),
diff --git a/tests/test_time.py b/tests/test_time.py
index 7699770..6488045 100644
--- a/tests/test_time.py
+++ b/tests/test_time.py
@@ -6,11 +6,13 @@
 import typing
 
 import pytest
-from freezegun import freeze_time
 
 import humanize
 from humanize import time
 
+freezegun = pytest.importorskip("freezegun")
+freeze_time = freezegun.freeze_time
+
 ONE_DAY_DELTA = dt.timedelta(days=1)
 
 # In seconds