diff --git a/pytests/src/pyfunctions.rs b/pytests/src/pyfunctions.rs
index 8d3da83cee3..ce7494f7c5f 100644
--- a/pytests/src/pyfunctions.rs
+++ b/pytests/src/pyfunctions.rs
@@ -87,11 +87,57 @@ fn with_custom_type_annotations<'py>(
     a
 }
 
+#[allow(clippy::too_many_arguments)]
+#[pyfunction(
+    signature = (
+        *,
+        ant = None,
+        bear = None,
+        cat = None,
+        dog = None,
+        elephant = None,
+        fox = None,
+        goat = None,
+        horse = None,
+        iguana = None,
+        jaguar = None,
+        koala = None,
+        lion = None,
+        monkey = None,
+        newt = None,
+        owl = None,
+        penguin = None
+    )
+)]
+fn many_keyword_arguments<'py>(
+    ant: Option<&'_ Bound<'py, PyAny>>,
+    bear: Option<&'_ Bound<'py, PyAny>>,
+    cat: Option<&'_ Bound<'py, PyAny>>,
+    dog: Option<&'_ Bound<'py, PyAny>>,
+    elephant: Option<&'_ Bound<'py, PyAny>>,
+    fox: Option<&'_ Bound<'py, PyAny>>,
+    goat: Option<&'_ Bound<'py, PyAny>>,
+    horse: Option<&'_ Bound<'py, PyAny>>,
+    iguana: Option<&'_ Bound<'py, PyAny>>,
+    jaguar: Option<&'_ Bound<'py, PyAny>>,
+    koala: Option<&'_ Bound<'py, PyAny>>,
+    lion: Option<&'_ Bound<'py, PyAny>>,
+    monkey: Option<&'_ Bound<'py, PyAny>>,
+    newt: Option<&'_ Bound<'py, PyAny>>,
+    owl: Option<&'_ Bound<'py, PyAny>>,
+    penguin: Option<&'_ Bound<'py, PyAny>>,
+) {
+    std::hint::black_box((
+        ant, bear, cat, dog, elephant, fox, goat, horse, iguana, jaguar, koala, lion, monkey, newt,
+        owl, penguin,
+    ));
+}
+
 #[pymodule]
 pub mod pyfunctions {
     #[pymodule_export]
     use super::{
-        args_kwargs, none, positional_only, simple, simple_args, simple_args_kwargs, simple_kwargs,
-        with_custom_type_annotations, with_typed_args,
+        args_kwargs, many_keyword_arguments, none, positional_only, simple, simple_args,
+        simple_args_kwargs, simple_kwargs, with_custom_type_annotations, with_typed_args,
     };
 }
diff --git a/pytests/stubs/pyfunctions.pyi b/pytests/stubs/pyfunctions.pyi
index 251ff160409..d2a4d78d8d9 100644
--- a/pytests/stubs/pyfunctions.pyi
+++ b/pytests/stubs/pyfunctions.pyi
@@ -1,6 +1,25 @@
 import typing
 
 def args_kwargs(*args, **kwargs) -> typing.Any: ...
+def many_keyword_arguments(
+    *,
+    ant: typing.Any | None = None,
+    bear: typing.Any | None = None,
+    cat: typing.Any | None = None,
+    dog: typing.Any | None = None,
+    elephant: typing.Any | None = None,
+    fox: typing.Any | None = None,
+    goat: typing.Any | None = None,
+    horse: typing.Any | None = None,
+    iguana: typing.Any | None = None,
+    jaguar: typing.Any | None = None,
+    koala: typing.Any | None = None,
+    lion: typing.Any | None = None,
+    monkey: typing.Any | None = None,
+    newt: typing.Any | None = None,
+    owl: typing.Any | None = None,
+    penguin: typing.Any | None = None,
+) -> typing.Any: ...
 def none() -> None: ...
 def positional_only(a: typing.Any, /, b: typing.Any) -> typing.Any: ...
 def simple(
diff --git a/pytests/tests/test_pyfunctions.py b/pytests/tests/test_pyfunctions.py
index b3897f289c6..e33d4d6f102 100644
--- a/pytests/tests/test_pyfunctions.py
+++ b/pytests/tests/test_pyfunctions.py
@@ -1,4 +1,4 @@
-from typing import Tuple
+from typing import Any, Tuple
 
 from pyo3_pytests import pyfunctions
 
@@ -118,3 +118,55 @@ def test_with_typed_args_rs(benchmark):
     rust = benchmark(pyfunctions.with_typed_args, True, 1, 1.2, "foo")
     py = with_typed_args_py(True, 1, 1.2, "foo")
     assert rust == py
+
+
+def many_keyword_arguments_py(
+    *,
+    ant: Any = None,
+    bear: Any = None,
+    cat: Any = None,
+    dog: Any = None,
+    elephant: Any = None,
+    fox: Any = None,
+    goat: Any = None,
+    horse: Any = None,
+    iguana: Any = None,
+    jaguar: Any = None,
+    koala: Any = None,
+    lion: Any = None,
+    monkey: Any = None,
+    newt: Any = None,
+    owl: Any = None,
+    penguin: Any = None,
+): ...
+
+
+def call_with_many_keyword_arguments(f) -> Any:
+    return f(
+        ant=True,
+        bear=1,
+        cat=1.2,
+        dog="foo",
+        elephant=None,
+        fox=8,
+        goat=9,
+        horse=10,
+        iguana=None,
+        jaguar=None,
+        koala=None,
+        lion=11,
+        owl=None,
+        penguin=None,
+    )
+
+
+def test_many_keyword_arguments_py(benchmark):
+    benchmark(call_with_many_keyword_arguments, many_keyword_arguments_py)
+
+
+def test_many_keyword_arguments_rs(benchmark):
+    rust = benchmark(
+        call_with_many_keyword_arguments, pyfunctions.many_keyword_arguments
+    )
+    py = call_with_many_keyword_arguments(many_keyword_arguments_py)
+    assert rust == py