diff --git a/Lib/test/test_inspect/test_inspect.py b/Lib/test/test_inspect/test_inspect.py
index 0ea029b977b3fc..4f3983d83c7c06 100644
--- a/Lib/test/test_inspect/test_inspect.py
+++ b/Lib/test/test_inspect/test_inspect.py
@@ -5916,6 +5916,7 @@ def test_sysconfig_module_has_signatures(self):
     def test_threading_module_has_signatures(self):
         import threading
         self._test_module_has_signatures(threading)
+        self.assertIsNotNone(inspect.signature(threading.__excepthook__))
 
     def test_thread_module_has_signatures(self):
         import _thread
diff --git a/Misc/NEWS.d/next/Library/2025-07-11-23-04-39.gh-issue-136549.oAi8u4.rst b/Misc/NEWS.d/next/Library/2025-07-11-23-04-39.gh-issue-136549.oAi8u4.rst
new file mode 100644
index 00000000000000..f3050ad5d5aa10
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2025-07-11-23-04-39.gh-issue-136549.oAi8u4.rst
@@ -0,0 +1 @@
+Fix signature of :func:`threading.excepthook`.
diff --git a/Modules/_threadmodule.c b/Modules/_threadmodule.c
index 8886a9d6bd0c8d..3540fead8e8e74 100644
--- a/Modules/_threadmodule.c
+++ b/Modules/_threadmodule.c
@@ -2330,7 +2330,7 @@ thread_excepthook(PyObject *module, PyObject *args)
 }
 
 PyDoc_STRVAR(excepthook_doc,
-"_excepthook($module, (exc_type, exc_value, exc_traceback, thread), /)\n\
+"_excepthook($module, args, /)\n\
 --\n\
 \n\
 Handle uncaught Thread.run() exception.");