diff --git a/lib/matplotlib/pyplot.py b/lib/matplotlib/pyplot.py
index cf5c9b4b739f..8da666499702 100644
--- a/lib/matplotlib/pyplot.py
+++ b/lib/matplotlib/pyplot.py
@@ -50,7 +50,7 @@
 import sys
 import threading
 import time
-from typing import TYPE_CHECKING, cast, overload
+from typing import IO, TYPE_CHECKING, cast, overload
 
 from cycler import cycler  # noqa: F401
 import matplotlib
@@ -338,8 +338,8 @@ def uninstall_repl_displayhook() -> None:
 
 # Ensure this appears in the pyplot docs.
 @_copy_docstring_and_deprecators(matplotlib.set_loglevel)
-def set_loglevel(*args, **kwargs) -> None:
-    return matplotlib.set_loglevel(*args, **kwargs)
+def set_loglevel(level: str) -> None:
+    return matplotlib.set_loglevel(level)
 
 
 @_copy_docstring_and_deprecators(Artist.findobj)
@@ -1251,11 +1251,11 @@ def draw() -> None:
 
 
 @_copy_docstring_and_deprecators(Figure.savefig)
-def savefig(*args, **kwargs) -> None:
+def savefig(fname: str | os.PathLike | IO, **kwargs) -> None:
     fig = gcf()
     # savefig default implementation has no return, so mypy is unhappy
     # presumably this is here because subclasses can return?
-    res = fig.savefig(*args, **kwargs)  # type: ignore[func-returns-value]
+    res = fig.savefig(fname, **kwargs)  # type: ignore[func-returns-value]
     fig.canvas.draw_idle()  # Need this if 'transparent=True', to reset colors.
     return res
 
diff --git a/lib/matplotlib/tests/test_pyplot.py b/lib/matplotlib/tests/test_pyplot.py
index ab713707bace..55f7c33cb52e 100644
--- a/lib/matplotlib/tests/test_pyplot.py
+++ b/lib/matplotlib/tests/test_pyplot.py
@@ -1,4 +1,5 @@
 import difflib
+import inspect
 
 import numpy as np
 import sys
@@ -484,3 +485,26 @@ def test_matshow():
 
     # Smoke test that matshow does not ask for a new figsize on the existing figure
     plt.matshow(arr, fignum=fig.number)
+
+
+def assert_same_signature(func1, func2):
+    """
+    Assert that `func1` and `func2` have the same arguments,
+    i.e. same parameter count, names and kinds.
+
+    :param func1: First function to check
+    :param func2: Second function to check
+    """
+    params1 = inspect.signature(func1).parameters
+    params2 = inspect.signature(func2).parameters
+
+    assert len(params1) == len(params2)
+    assert all([
+        params1[p].name == params2[p].name and
+        params1[p].kind == params2[p].kind
+        for p in params1
+    ])
+
+
+def test_setloglevel_signature():
+    assert_same_signature(plt.set_loglevel, mpl.set_loglevel)