python
diff --git a/Lib/test/test_inspect.py b/Lib/test/test_inspect.py
@@ -2766,6 +2766,11 @@ class ThisWorksNow:
         # Regression test for issue #20586
         test_callable(_testcapi.docstring_with_signature_but_no_doc)
 
+        # Regression test for gh-104955
+        method = bytearray.__release_buffer__
+        sig = test_unbound_method(method)
+        self.assertEqual(list(sig.parameters), ['self', 'buffer'])
+
     @cpython_only
     @unittest.skipIf(MISSING_C_DOCSTRINGS,
                      "Signature information for builtins requires docstrings")

diff --git a/Misc/NEWS.d/next/Core and Builtins/2023-05-25-21-40-39.gh-issue-104955.LZx7jf.rst b/Misc/NEWS.d/next/Core and Builtins/2023-05-25-21-40-39.gh-issue-104955.LZx7jf.rst
@@ -0,0 +1,2 @@
+Fix signature for the new :meth:`~object.__release_buffer__` slot. Patch by Jelle
+Zijlstra.
@@ -9428,7 +9428,7 @@ static pytype_slotdef slotdefs[] = {
             "__buffer__($self, flags, /)\n--\n\n"
             "Return a buffer object that exposes the underlying memory of the object."),
     BUFSLOT(__release_buffer__, bf_releasebuffer, slot_bf_releasebuffer, wrap_releasebuffer,
-            "__release_buffer__($self, /)\n--\n\n"
+            "__release_buffer__($self, buffer, /)\n--\n\n"
             "Release the buffer object that exposes the underlying memory of the object."),
 
     AMSLOT(__await__, am_await, slot_am_await, wrap_unaryfunc,
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,2 @@
		Fix signature for the new :meth:`~object.__release_buffer__` slot. Patch by Jelle
		Zijlstra.