diff --git a/Lib/test/clinic.test.c b/Lib/test/clinic.test.c
index 3dca8b8d1ed9b99..2ac153ac43e7029 100644
--- a/Lib/test/clinic.test.c
+++ b/Lib/test/clinic.test.c
@@ -5431,6 +5431,12 @@ Test_property_set(PyObject *self, PyObject *value, void *Py_UNUSED(context))
 {
     int return_value;
 
+    if (value == NULL) {
+        PyErr_Format(PyExc_AttributeError,
+                     "attribute 'property' of '%.100s' objects cannot be deleted",
+                     Py_TYPE(self)->tp_name);
+        return -1;
+    }
     return_value = Test_property_set_impl((TestObj *)self, value);
 
     return return_value;
@@ -5438,7 +5444,40 @@ Test_property_set(PyObject *self, PyObject *value, void *Py_UNUSED(context))
 
 static int
 Test_property_set_impl(TestObj *self, PyObject *value)
-/*[clinic end generated code: output=49f925ab2a33b637 input=3bc3f46a23c83a88]*/
+/*[clinic end generated code: output=ec103a151cf51d25 input=3bc3f46a23c83a88]*/
+
+/*[clinic input]
+@setter
+@deleter
+Test.settable_and_deletable
+[clinic start generated code]*/
+
+#if !defined(Test_settable_and_deletable_DOCSTR)
+#  define Test_settable_and_deletable_DOCSTR NULL
+#endif
+#if defined(TEST_SETTABLE_AND_DELETABLE_GETSETDEF)
+#  undef TEST_SETTABLE_AND_DELETABLE_GETSETDEF
+#  define TEST_SETTABLE_AND_DELETABLE_GETSETDEF {"settable_and_deletable", (getter)Test_settable_and_deletable_get, (setter)Test_settable_and_deletable_set, Test_settable_and_deletable_DOCSTR},
+#else
+#  define TEST_SETTABLE_AND_DELETABLE_GETSETDEF {"settable_and_deletable", NULL, (setter)Test_settable_and_deletable_set, NULL},
+#endif
+
+static int
+Test_settable_and_deletable_set_impl(TestObj *self, PyObject *value);
+
+static int
+Test_settable_and_deletable_set(PyObject *self, PyObject *value, void *Py_UNUSED(context))
+{
+    int return_value;
+
+    return_value = Test_settable_and_deletable_set_impl((TestObj *)self, value);
+
+    return return_value;
+}
+
+static int
+Test_settable_and_deletable_set_impl(TestObj *self, PyObject *value)
+/*[clinic end generated code: output=479986d499b2f56d input=f5647f3511b9daea]*/
 
 /*[clinic input]
 @setter
@@ -5463,6 +5502,12 @@ Test_setter_first_with_docstr_set(PyObject *self, PyObject *value, void *Py_UNUS
 {
     int return_value;
 
+    if (value == NULL) {
+        PyErr_Format(PyExc_AttributeError,
+                     "attribute 'setter_first_with_docstr' of '%.100s' objects cannot be deleted",
+                     Py_TYPE(self)->tp_name);
+        return -1;
+    }
     return_value = Test_setter_first_with_docstr_set_impl((TestObj *)self, value);
 
     return return_value;
@@ -5470,7 +5515,7 @@ Test_setter_first_with_docstr_set(PyObject *self, PyObject *value, void *Py_UNUS
 
 static int
 Test_setter_first_with_docstr_set_impl(TestObj *self, PyObject *value)
-/*[clinic end generated code: output=5aaf44373c0af545 input=31a045ce11bbe961]*/
+/*[clinic end generated code: output=eac8bafcaa50aa51 input=31a045ce11bbe961]*/
 
 /*[clinic input]
 @getter
diff --git a/Lib/test/test_clinic.py b/Lib/test/test_clinic.py
index 1dc1c4eaaaba196..f0dc62967f6a776 100644
--- a/Lib/test/test_clinic.py
+++ b/Lib/test/test_clinic.py
@@ -794,6 +794,102 @@ def test_ignore_preprocessor_in_comments(self):
             """)
             self.clinic.parse(raw)
 
+    def test_getset_in_ifdef(self):
+        block = """
+            /*[clinic input]
+            output everything block
+            class Foo "FooObject *" "&Foo_Type"
+            [clinic start generated code]*/
+            #ifdef CONDITION
+            /*[clinic input]
+            @getter
+            Foo.property
+            [clinic start generated code]*/
+            /*[clinic input]
+            @setter
+            Foo.property
+            [clinic start generated code]*/
+            #endif
+        """
+        generated = self.clinic.parse(dedent(block))
+        self.assertIn("#if defined(CONDITION)", generated)
+        # The getset is undefined if the condition is false.
+        self.assertIn("#ifndef FOO_PROPERTY_GETSETDEF\n"
+                      "    #define FOO_PROPERTY_GETSETDEF\n"
+                      "#endif /* !defined(FOO_PROPERTY_GETSETDEF) */",
+                      generated)
+
+    def test_getset_duplicate(self):
+        for annotation in "@getter", "@setter":
+            with self.subTest(annotation=annotation):
+                self.clinic = _make_clinic(filename="test.c")
+                block = f"""
+                    /*[clinic input]
+                    class Foo "FooObject *" "&Foo_Type"
+                    [clinic start generated code]*/
+                    /*[clinic input]
+                    {annotation}
+                    Foo.property
+                    [clinic start generated code]*/
+                    /*[clinic input]
+                    {annotation}
+                    Foo.property
+                    [clinic start generated code]*/
+                """
+                kind = 'setter' if annotation == '@setter' else 'getter'
+                err = f"Cannot apply @{kind} to 'Foo.property' twice"
+                self.expect_failure(block, err, lineno=10)
+
+    def test_getset_different_c_basename(self):
+        block = """
+            /*[clinic input]
+            class Foo "FooObject *" "&Foo_Type"
+            [clinic start generated code]*/
+            /*[clinic input]
+            @getter
+            Foo.property as foo_get
+            [clinic start generated code]*/
+            /*[clinic input]
+            @setter
+            Foo.property as foo_set
+            [clinic start generated code]*/
+        """
+        err = "The accessors of 'Foo.property' must have the same C basename"
+        self.expect_failure(block, err, lineno=10)
+
+    def test_setter_deletion_check(self):
+        block = """
+            /*[clinic input]
+            output everything block
+            class Foo "FooObject *" "&Foo_Type"
+            [clinic start generated code]*/
+            /*[clinic input]
+            @setter
+            Foo.property
+            [clinic start generated code]*/
+        """
+        generated = self.clinic.parse(dedent(block))
+        self.assertIn("if (value == NULL) {", generated)
+        self.assertIn("\"attribute 'property' of '%.100s' objects "
+                      "cannot be deleted\"", generated)
+
+    def test_deleter(self):
+        # @deleter means that the setter is called with NULL to delete
+        # the attribute, so it checks the value itself.
+        block = """
+            /*[clinic input]
+            output everything block
+            class Foo "FooObject *" "&Foo_Type"
+            [clinic start generated code]*/
+            /*[clinic input]
+            @setter
+            @deleter
+            Foo.property
+            [clinic start generated code]*/
+        """
+        generated = self.clinic.parse(dedent(block))
+        self.assertNotIn("if (value == NULL) {", generated)
+
     def test_var_keyword_non_dict(self):
         err = "'var_keyword_object' is not a valid converter"
         block = """
@@ -2671,7 +2767,7 @@ class Foo "" ""
                     {annotation}
                     Foo.property -> int
                 """
-                expected_error = f"{annotation} method cannot define a return type"
+                expected_error = "@getter and @setter methods cannot define a return type"
                 self.expect_failure(block, expected_error, lineno=3)
 
                 block = f"""
@@ -2682,7 +2778,7 @@ class Foo "" ""
                        obj: int
                        /
                 """
-                expected_error = f"{annotation} methods cannot define parameters"
+                expected_error = "@getter and @setter methods cannot define parameters"
                 self.expect_failure(block, expected_error)
 
     def test_setter_docstring(self):
@@ -2725,9 +2821,51 @@ class Foo "" ""
                     {dup[1]}
                     Foo.property -> int
                 """
-                expected_error = "Cannot apply both @getter and @setter to the same function!"
+                expected_error = (f"Can't set {dup[1]}, "
+                                  f"function is not a normal callable")
                 self.expect_failure(block, expected_error, lineno=3)
 
+    def test_deleter_without_setter(self):
+        block = """
+            module foo
+            class Foo "" ""
+            @deleter
+            Foo.property
+        """
+        expected_error = "Can't set @deleter, @setter is not applied"
+        self.expect_failure(block, expected_error, lineno=2)
+
+        block = """
+            module foo
+            class Foo "" ""
+            @deleter
+            @setter
+            Foo.property
+        """
+        self.expect_failure(block, expected_error, lineno=2)
+
+    def test_deleter_twice(self):
+        block = """
+            module foo
+            class Foo "" ""
+            @setter
+            @deleter
+            @deleter
+            Foo.property
+        """
+        expected_error = "Cannot apply @deleter twice to the same function!"
+        self.expect_failure(block, expected_error, lineno=4)
+
+    def test_setter_and_deleter(self):
+        function = self.parse_function("""
+            module foo
+            class Foo "" ""
+            @setter
+            @deleter
+            Foo.property
+        """, signatures_in_block=3, function_index=2)
+        self.assertEqual(function.kind, FunctionKind.SETTER_AND_DELETER)
+
     def test_getset_no_class(self):
         for annotation in "@getter", "@setter":
             with self.subTest(annotation=annotation):
diff --git a/Misc/NEWS.d/next/Library/2026-08-14-12-46-07.gh-issue-113318.DYGQjo.rst b/Misc/NEWS.d/next/Library/2026-08-14-12-46-07.gh-issue-113318.DYGQjo.rst
new file mode 100644
index 000000000000000..4cd4acd01886368
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2026-08-14-12-46-07.gh-issue-113318.DYGQjo.rst
@@ -0,0 +1,5 @@
+Fix crashes when deleting an attribute whose setter is generated by Argument
+Clinic and is not prepared for deletion, among them
+:attr:`frame.f_trace_opcodes` and the ``context``, ``owner`` and ``session``
+attributes of ``_ssl._SSLSocket``.
+Deleting such attribute now raises :exc:`AttributeError`.
diff --git a/Misc/NEWS.d/next/Tools-Demos/2026-08-14-12-45-57.gh-issue-113318.G1B0oH.rst b/Misc/NEWS.d/next/Tools-Demos/2026-08-14-12-45-57.gh-issue-113318.G1B0oH.rst
new file mode 100644
index 000000000000000..3ea0a37288fe880
--- /dev/null
+++ b/Misc/NEWS.d/next/Tools-Demos/2026-08-14-12-45-57.gh-issue-113318.G1B0oH.rst
@@ -0,0 +1,6 @@
+Fix Argument Clinic for ``@getter`` and ``@setter`` in a preprocessor
+conditional block.
+It failed with an internal error.
+Argument Clinic now also rejects the accessors of the same attribute with
+different C basenames, and the same accessor defined twice, which silently
+generated invalid or duplicated entries of :c:type:`PyGetSetDef`.
diff --git a/Modules/_asynciomodule.c b/Modules/_asynciomodule.c
index 41384b388142ccc..00b20901df69964 100644
--- a/Modules/_asynciomodule.c
+++ b/Modules/_asynciomodule.c
@@ -1372,13 +1372,14 @@ _asyncio_Future__asyncio_future_blocking_get_impl(FutureObj *self)
 /*[clinic input]
 @critical_section
 @setter
+@deleter
 _asyncio.Future._asyncio_future_blocking
 [clinic start generated code]*/
 
 static int
 _asyncio_Future__asyncio_future_blocking_set_impl(FutureObj *self,
                                                   PyObject *value)
-/*[clinic end generated code: output=0686d1cb024a7453 input=3fd4a5f95df788b7]*/
+/*[clinic end generated code: output=0686d1cb024a7453 input=68cea090c8793dd4]*/
 
 {
     if (future_ensure_alive(self)) {
@@ -1420,12 +1421,13 @@ _asyncio_Future__log_traceback_get_impl(FutureObj *self)
 /*[clinic input]
 @critical_section
 @setter
+@deleter
 _asyncio.Future._log_traceback
 [clinic start generated code]*/
 
 static int
 _asyncio_Future__log_traceback_set_impl(FutureObj *self, PyObject *value)
-/*[clinic end generated code: output=9ce8e19504f42f54 input=30ac8217754b08c2]*/
+/*[clinic end generated code: output=9ce8e19504f42f54 input=469dbdd15343d39f]*/
 {
     if (value == NULL) {
         PyErr_SetString(PyExc_AttributeError, "cannot delete attribute");
@@ -1585,12 +1587,13 @@ _asyncio_Future__cancel_message_get_impl(FutureObj *self)
 /*[clinic input]
 @critical_section
 @setter
+@deleter
 _asyncio.Future._cancel_message
 [clinic start generated code]*/
 
 static int
 _asyncio_Future__cancel_message_set_impl(FutureObj *self, PyObject *value)
-/*[clinic end generated code: output=0854b2f77bff2209 input=f461d17f2d891fad]*/
+/*[clinic end generated code: output=0854b2f77bff2209 input=68b3a24731dfb629]*/
 {
     if (value == NULL) {
         PyErr_SetString(PyExc_AttributeError, "cannot delete attribute");
@@ -2443,12 +2446,13 @@ _asyncio_Task__log_destroy_pending_get_impl(TaskObj *self)
 /*[clinic input]
 @critical_section
 @setter
+@deleter
 _asyncio.Task._log_destroy_pending
 [clinic start generated code]*/
 
 static int
 _asyncio_Task__log_destroy_pending_set_impl(TaskObj *self, PyObject *value)
-/*[clinic end generated code: output=7ebc030bb92ec5ce input=49b759c97d1216a4]*/
+/*[clinic end generated code: output=7ebc030bb92ec5ce input=31af83e8bf57ac6f]*/
 {
     if (value == NULL) {
         PyErr_SetString(PyExc_AttributeError, "cannot delete attribute");
diff --git a/Modules/_ctypes/_ctypes.c b/Modules/_ctypes/_ctypes.c
index adfdf44e53604e3..34d3c1685c69fcb 100644
--- a/Modules/_ctypes/_ctypes.c
+++ b/Modules/_ctypes/_ctypes.c
@@ -598,13 +598,14 @@ _ctypes_CType_Type___pointer_type___get_impl(PyObject *self)
 
 /*[clinic input]
 @setter
+@deleter
 _ctypes.CType_Type.__pointer_type__
 
 [clinic start generated code]*/
 
 static int
 _ctypes_CType_Type___pointer_type___set_impl(PyObject *self, PyObject *value)
-/*[clinic end generated code: output=6259be8ea21693fa input=a05055fc7f4714b6]*/
+/*[clinic end generated code: output=6259be8ea21693fa input=7e24bceb1676349b]*/
 {
     ctypes_state *st = get_module_state_by_def(Py_TYPE(self));
     StgInfo *info;
@@ -1480,12 +1481,13 @@ class _ctypes.PyCArrayType_Type "CDataObject *" "clinic_state()->PyCArrayType_Ty
 /*[clinic input]
 @critical_section
 @setter
+@deleter
 _ctypes.PyCArrayType_Type.raw
 [clinic start generated code]*/
 
 static int
 _ctypes_PyCArrayType_Type_raw_set_impl(CDataObject *self, PyObject *value)
-/*[clinic end generated code: output=cf9b2a9fd92e9ecb input=a3717561efc45efd]*/
+/*[clinic end generated code: output=cf9b2a9fd92e9ecb input=13881e1662127207]*/
 {
     char *ptr;
     Py_ssize_t size;
@@ -1550,12 +1552,13 @@ _ctypes_PyCArrayType_Type_value_get_impl(CDataObject *self)
 /*[clinic input]
 @critical_section
 @setter
+@deleter
 _ctypes.PyCArrayType_Type.value
 [clinic start generated code]*/
 
 static int
 _ctypes_PyCArrayType_Type_value_set_impl(CDataObject *self, PyObject *value)
-/*[clinic end generated code: output=39ad655636a28dd5 input=e2e6385fc6ab1a29]*/
+/*[clinic end generated code: output=39ad655636a28dd5 input=167f0935cbb8d489]*/
 {
     const char *ptr;
     Py_ssize_t size;
@@ -3664,12 +3667,13 @@ _validate_paramflags(ctypes_state *st, PyTypeObject *type, PyObject *paramflags,
 /*[clinic input]
 @critical_section
 @setter
+@deleter
 _ctypes.CFuncPtr.errcheck
 [clinic start generated code]*/
 
 static int
 _ctypes_CFuncPtr_errcheck_set_impl(PyCFuncPtrObject *self, PyObject *value)
-/*[clinic end generated code: output=6580cf1ffdf3b9fb input=84930bb16c490b33]*/
+/*[clinic end generated code: output=6580cf1ffdf3b9fb input=bcd5d3ed1a0c36e9]*/
 {
     if (value && !PyCallable_Check(value)) {
         PyErr_SetString(PyExc_TypeError,
@@ -3701,13 +3705,14 @@ _ctypes_CFuncPtr_errcheck_get_impl(PyCFuncPtrObject *self)
 
 /*[clinic input]
 @setter
+@deleter
 @critical_section
 _ctypes.CFuncPtr.restype
 [clinic start generated code]*/
 
 static int
 _ctypes_CFuncPtr_restype_set_impl(PyCFuncPtrObject *self, PyObject *value)
-/*[clinic end generated code: output=0be0a086abbabf18 input=683c3bef4562ccc6]*/
+/*[clinic end generated code: output=0be0a086abbabf18 input=ffc941a26dbb31f3]*/
 {
     PyObject *checker;
     if (value == NULL) {
@@ -3764,13 +3769,14 @@ _ctypes_CFuncPtr_restype_get_impl(PyCFuncPtrObject *self)
 
 /*[clinic input]
 @setter
+@deleter
 @critical_section
 _ctypes.CFuncPtr.argtypes
 [clinic start generated code]*/
 
 static int
 _ctypes_CFuncPtr_argtypes_set_impl(PyCFuncPtrObject *self, PyObject *value)
-/*[clinic end generated code: output=596a36e2ae89d7d1 input=c4627573e980aa8b]*/
+/*[clinic end generated code: output=596a36e2ae89d7d1 input=fd012f1fd7cc35be]*/
 {
     if (value == NULL || value == Py_None) {
         atomic_xsetref(&self->argtypes, NULL);
@@ -5413,12 +5419,13 @@ class _ctypes.Simple "CDataObject *" "clinic_state()->Simple_Type"
 /*[clinic input]
 @critical_section
 @setter
+@deleter
 _ctypes.Simple.value
 [clinic start generated code]*/
 
 static int
 _ctypes_Simple_value_set_impl(CDataObject *self, PyObject *value)
-/*[clinic end generated code: output=f267186118939863 input=977af9dc9e71e857]*/
+/*[clinic end generated code: output=f267186118939863 input=4e6c1143d17c2c3f]*/
 {
     PyObject *result;
 
diff --git a/Modules/_io/textio.c b/Modules/_io/textio.c
index ea8ed2713d8a146..d48fb62ee0569b8 100644
--- a/Modules/_io/textio.c
+++ b/Modules/_io/textio.c
@@ -3399,12 +3399,13 @@ _io_TextIOWrapper__CHUNK_SIZE_get_impl(textio *self)
 /*[clinic input]
 @critical_section
 @setter
+@deleter
 _io.TextIOWrapper._CHUNK_SIZE
 [clinic start generated code]*/
 
 static int
 _io_TextIOWrapper__CHUNK_SIZE_set_impl(textio *self, PyObject *value)
-/*[clinic end generated code: output=edb86d2db660a5ab input=32fc99861db02a0a]*/
+/*[clinic end generated code: output=edb86d2db660a5ab input=e7c44a734efeddc3]*/
 {
     Py_ssize_t n;
     CHECK_ATTACHED_INT(self);
diff --git a/Modules/_sqlite/clinic/cursor.c.h b/Modules/_sqlite/clinic/cursor.c.h
index 3cad9f3aef5ecd5..689466b1c2b85a1 100644
--- a/Modules/_sqlite/clinic/cursor.c.h
+++ b/Modules/_sqlite/clinic/cursor.c.h
@@ -367,8 +367,14 @@ _sqlite3_Cursor_arraysize_set(PyObject *self, PyObject *value, void *Py_UNUSED(c
 {
     int return_value;
 
+    if (value == NULL) {
+        PyErr_Format(PyExc_AttributeError,
+                     "attribute 'arraysize' of '%.100s' objects cannot be deleted",
+                     Py_TYPE(self)->tp_name);
+        return -1;
+    }
     return_value = _sqlite3_Cursor_arraysize_set_impl((pysqlite_Cursor *)self, value);
 
     return return_value;
 }
-/*[clinic end generated code: output=a0e3ebba9e4d0ece input=a9049054013a1b77]*/
+/*[clinic end generated code: output=e7b20358f8213fd7 input=a9049054013a1b77]*/
diff --git a/Modules/clinic/_ssl.c.h b/Modules/clinic/_ssl.c.h
index e337ed2390a1fc4..62d52fc5f1aa5dd 100644
--- a/Modules/clinic/_ssl.c.h
+++ b/Modules/clinic/_ssl.c.h
@@ -386,6 +386,12 @@ _ssl__SSLSocket_context_set(PyObject *self, PyObject *value, void *Py_UNUSED(con
 {
     int return_value;
 
+    if (value == NULL) {
+        PyErr_Format(PyExc_AttributeError,
+                     "attribute 'context' of '%.100s' objects cannot be deleted",
+                     Py_TYPE(self)->tp_name);
+        return -1;
+    }
     Py_BEGIN_CRITICAL_SECTION(self);
     return_value = _ssl__SSLSocket_context_set_impl((PySSLSocket *)self, value);
     Py_END_CRITICAL_SECTION();
@@ -509,6 +515,12 @@ _ssl__SSLSocket_owner_set(PyObject *self, PyObject *value, void *Py_UNUSED(conte
 {
     int return_value;
 
+    if (value == NULL) {
+        PyErr_Format(PyExc_AttributeError,
+                     "attribute 'owner' of '%.100s' objects cannot be deleted",
+                     Py_TYPE(self)->tp_name);
+        return -1;
+    }
     Py_BEGIN_CRITICAL_SECTION(self);
     return_value = _ssl__SSLSocket_owner_set_impl((PySSLSocket *)self, value);
     Py_END_CRITICAL_SECTION();
@@ -914,6 +926,12 @@ _ssl__SSLSocket_session_set(PyObject *self, PyObject *value, void *Py_UNUSED(con
 {
     int return_value;
 
+    if (value == NULL) {
+        PyErr_Format(PyExc_AttributeError,
+                     "attribute 'session' of '%.100s' objects cannot be deleted",
+                     Py_TYPE(self)->tp_name);
+        return -1;
+    }
     Py_BEGIN_CRITICAL_SECTION(self);
     return_value = _ssl__SSLSocket_session_set_impl((PySSLSocket *)self, value);
     Py_END_CRITICAL_SECTION();
@@ -1342,6 +1360,12 @@ _ssl__SSLContext_verify_mode_set(PyObject *self, PyObject *value, void *Py_UNUSE
 {
     int return_value;
 
+    if (value == NULL) {
+        PyErr_Format(PyExc_AttributeError,
+                     "attribute 'verify_mode' of '%.100s' objects cannot be deleted",
+                     Py_TYPE(self)->tp_name);
+        return -1;
+    }
     Py_BEGIN_CRITICAL_SECTION(self);
     return_value = _ssl__SSLContext_verify_mode_set_impl((PySSLContext *)self, value);
     Py_END_CRITICAL_SECTION();
@@ -1392,6 +1416,12 @@ _ssl__SSLContext_verify_flags_set(PyObject *self, PyObject *value, void *Py_UNUS
 {
     int return_value;
 
+    if (value == NULL) {
+        PyErr_Format(PyExc_AttributeError,
+                     "attribute 'verify_flags' of '%.100s' objects cannot be deleted",
+                     Py_TYPE(self)->tp_name);
+        return -1;
+    }
     Py_BEGIN_CRITICAL_SECTION(self);
     return_value = _ssl__SSLContext_verify_flags_set_impl((PySSLContext *)self, value);
     Py_END_CRITICAL_SECTION();
@@ -1443,6 +1473,12 @@ _ssl__SSLContext_minimum_version_set(PyObject *self, PyObject *value, void *Py_U
 {
     int return_value;
 
+    if (value == NULL) {
+        PyErr_Format(PyExc_AttributeError,
+                     "attribute 'minimum_version' of '%.100s' objects cannot be deleted",
+                     Py_TYPE(self)->tp_name);
+        return -1;
+    }
     Py_BEGIN_CRITICAL_SECTION(self);
     return_value = _ssl__SSLContext_minimum_version_set_impl((PySSLContext *)self, value);
     Py_END_CRITICAL_SECTION();
@@ -1494,6 +1530,12 @@ _ssl__SSLContext_maximum_version_set(PyObject *self, PyObject *value, void *Py_U
 {
     int return_value;
 
+    if (value == NULL) {
+        PyErr_Format(PyExc_AttributeError,
+                     "attribute 'maximum_version' of '%.100s' objects cannot be deleted",
+                     Py_TYPE(self)->tp_name);
+        return -1;
+    }
     Py_BEGIN_CRITICAL_SECTION(self);
     return_value = _ssl__SSLContext_maximum_version_set_impl((PySSLContext *)self, value);
     Py_END_CRITICAL_SECTION();
@@ -1551,6 +1593,12 @@ _ssl__SSLContext_num_tickets_set(PyObject *self, PyObject *value, void *Py_UNUSE
 {
     int return_value;
 
+    if (value == NULL) {
+        PyErr_Format(PyExc_AttributeError,
+                     "attribute 'num_tickets' of '%.100s' objects cannot be deleted",
+                     Py_TYPE(self)->tp_name);
+        return -1;
+    }
     Py_BEGIN_CRITICAL_SECTION(self);
     return_value = _ssl__SSLContext_num_tickets_set_impl((PySSLContext *)self, value);
     Py_END_CRITICAL_SECTION();
@@ -1633,6 +1681,12 @@ _ssl__SSLContext_options_set(PyObject *self, PyObject *value, void *Py_UNUSED(co
 {
     int return_value;
 
+    if (value == NULL) {
+        PyErr_Format(PyExc_AttributeError,
+                     "attribute 'options' of '%.100s' objects cannot be deleted",
+                     Py_TYPE(self)->tp_name);
+        return -1;
+    }
     Py_BEGIN_CRITICAL_SECTION(self);
     return_value = _ssl__SSLContext_options_set_impl((PySSLContext *)self, value);
     Py_END_CRITICAL_SECTION();
@@ -1683,6 +1737,12 @@ _ssl__SSLContext__host_flags_set(PyObject *self, PyObject *value, void *Py_UNUSE
 {
     int return_value;
 
+    if (value == NULL) {
+        PyErr_Format(PyExc_AttributeError,
+                     "attribute '_host_flags' of '%.100s' objects cannot be deleted",
+                     Py_TYPE(self)->tp_name);
+        return -1;
+    }
     Py_BEGIN_CRITICAL_SECTION(self);
     return_value = _ssl__SSLContext__host_flags_set_impl((PySSLContext *)self, value);
     Py_END_CRITICAL_SECTION();
@@ -1733,6 +1793,12 @@ _ssl__SSLContext_check_hostname_set(PyObject *self, PyObject *value, void *Py_UN
 {
     int return_value;
 
+    if (value == NULL) {
+        PyErr_Format(PyExc_AttributeError,
+                     "attribute 'check_hostname' of '%.100s' objects cannot be deleted",
+                     Py_TYPE(self)->tp_name);
+        return -1;
+    }
     Py_BEGIN_CRITICAL_SECTION(self);
     return_value = _ssl__SSLContext_check_hostname_set_impl((PySSLContext *)self, value);
     Py_END_CRITICAL_SECTION();
@@ -2265,6 +2331,12 @@ _ssl__SSLContext_sni_callback_set(PyObject *self, PyObject *value, void *Py_UNUS
 {
     int return_value;
 
+    if (value == NULL) {
+        PyErr_Format(PyExc_AttributeError,
+                     "attribute 'sni_callback' of '%.100s' objects cannot be deleted",
+                     Py_TYPE(self)->tp_name);
+        return -1;
+    }
     Py_BEGIN_CRITICAL_SECTION(self);
     return_value = _ssl__SSLContext_sni_callback_set_impl((PySSLContext *)self, value);
     Py_END_CRITICAL_SECTION();
@@ -3326,4 +3398,4 @@ _ssl_enum_crls(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyObje
 #ifndef _SSL_ENUM_CRLS_METHODDEF
     #define _SSL_ENUM_CRLS_METHODDEF
 #endif /* !defined(_SSL_ENUM_CRLS_METHODDEF) */
-/*[clinic end generated code: output=aef2e74b706c6106 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=3a5bdd8db17e32b1 input=a9049054013a1b77]*/
diff --git a/Objects/clinic/frameobject.c.h b/Objects/clinic/frameobject.c.h
index 327896f4b97c684..0ba1f3b6618ffef 100644
--- a/Objects/clinic/frameobject.c.h
+++ b/Objects/clinic/frameobject.c.h
@@ -265,6 +265,12 @@ frame_trace_opcodes_set(PyObject *self, PyObject *value, void *Py_UNUSED(context
 {
     int return_value;
 
+    if (value == NULL) {
+        PyErr_Format(PyExc_AttributeError,
+                     "attribute 'f_trace_opcodes' of '%.100s' objects cannot be deleted",
+                     Py_TYPE(self)->tp_name);
+        return -1;
+    }
     Py_BEGIN_CRITICAL_SECTION(self);
     return_value = frame_trace_opcodes_set_impl((PyFrameObject *)self, value);
     Py_END_CRITICAL_SECTION();
@@ -433,4 +439,4 @@ frame___sizeof__(PyObject *self, PyObject *Py_UNUSED(ignored))
 
     return return_value;
 }
-/*[clinic end generated code: output=74abf652547c0c11 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=a35726b44114286a input=a9049054013a1b77]*/
diff --git a/Objects/exceptions.c b/Objects/exceptions.c
index fb546ad2673576d..cc3e03baa4c7dfe 100644
--- a/Objects/exceptions.c
+++ b/Objects/exceptions.c
@@ -346,12 +346,13 @@ BaseException_args_get_impl(PyBaseExceptionObject *self)
 /*[clinic input]
 @critical_section
 @setter
+@deleter
 BaseException.args
 [clinic start generated code]*/
 
 static int
 BaseException_args_set_impl(PyBaseExceptionObject *self, PyObject *value)
-/*[clinic end generated code: output=331137e11d8f9e80 input=2400047ea5970a84]*/
+/*[clinic end generated code: output=331137e11d8f9e80 input=177ad350c8b45219]*/
 {
     PyObject *seq;
     if (value == NULL) {
@@ -385,13 +386,14 @@ BaseException___traceback___get_impl(PyBaseExceptionObject *self)
 /*[clinic input]
 @critical_section
 @setter
+@deleter
 BaseException.__traceback__
 [clinic start generated code]*/
 
 static int
 BaseException___traceback___set_impl(PyBaseExceptionObject *self,
                                      PyObject *value)
-/*[clinic end generated code: output=a82c86d9f29f48f0 input=12676035676badad]*/
+/*[clinic end generated code: output=a82c86d9f29f48f0 input=53a1df586023d786]*/
 {
     if (value == NULL) {
         PyErr_SetString(PyExc_TypeError, "__traceback__ may not be deleted");
@@ -430,13 +432,14 @@ BaseException___context___get_impl(PyBaseExceptionObject *self)
 /*[clinic input]
 @critical_section
 @setter
+@deleter
 BaseException.__context__
 [clinic start generated code]*/
 
 static int
 BaseException___context___set_impl(PyBaseExceptionObject *self,
                                    PyObject *value)
-/*[clinic end generated code: output=b4cb52dcca1da3bd input=c0971adf47fa1858]*/
+/*[clinic end generated code: output=b4cb52dcca1da3bd input=fe79e7c0a0854004]*/
 {
     if (value == NULL) {
         PyErr_SetString(PyExc_TypeError, "__context__ may not be deleted");
@@ -473,13 +476,14 @@ BaseException___cause___get_impl(PyBaseExceptionObject *self)
 /*[clinic input]
 @critical_section
 @setter
+@deleter
 BaseException.__cause__
 [clinic start generated code]*/
 
 static int
 BaseException___cause___set_impl(PyBaseExceptionObject *self,
                                  PyObject *value)
-/*[clinic end generated code: output=6161315398aaf541 input=e1b403c0bde3f62a]*/
+/*[clinic end generated code: output=6161315398aaf541 input=3fdd9a0d1674abc9]*/
 {
     if (value == NULL) {
         PyErr_SetString(PyExc_TypeError, "__cause__ may not be deleted");
diff --git a/Objects/frameobject.c b/Objects/frameobject.c
index c50cbeaada3c406..2d07f1c2a6c4421 100644
--- a/Objects/frameobject.c
+++ b/Objects/frameobject.c
@@ -1643,12 +1643,13 @@ static bool frame_is_suspended(PyFrameObject *frame)
 /*[clinic input]
 @critical_section
 @setter
+@deleter
 frame.f_lineno as frame_lineno
 [clinic start generated code]*/
 
 static int
 frame_lineno_set_impl(PyFrameObject *self, PyObject *value)
-/*[clinic end generated code: output=e64c86ff6be64292 input=36ed3c896b27fb91]*/
+/*[clinic end generated code: output=e64c86ff6be64292 input=c814c375c6bd16ba]*/
 {
     PyCodeObject *code = _PyFrame_GetCode(self->f_frame);
     if (value == NULL) {
@@ -1868,12 +1869,13 @@ frame_trace_get_impl(PyFrameObject *self)
 @permit_long_summary
 @critical_section
 @setter
+@deleter
 frame.f_trace as frame_trace
 [clinic start generated code]*/
 
 static int
 frame_trace_set_impl(PyFrameObject *self, PyObject *value)
-/*[clinic end generated code: output=d6fe08335cf76ae4 input=e57380734815dac5]*/
+/*[clinic end generated code: output=d6fe08335cf76ae4 input=9fb7a5805196eae2]*/
 {
     if (value == Py_None) {
         value = NULL;
diff --git a/Objects/funcobject.c b/Objects/funcobject.c
index 0c1fab7f6d33a8a..0481adadf668f8d 100644
--- a/Objects/funcobject.c
+++ b/Objects/funcobject.c
@@ -926,12 +926,13 @@ function___annotate___get_impl(PyFunctionObject *self)
 /*[clinic input]
 @critical_section
 @setter
+@deleter
 function.__annotate__
 [clinic start generated code]*/
 
 static int
 function___annotate___set_impl(PyFunctionObject *self, PyObject *value)
-/*[clinic end generated code: output=05b7dfc07ada66cd input=eb6225e358d97448]*/
+/*[clinic end generated code: output=05b7dfc07ada66cd input=4bcfad0bdcfec768]*/
 {
     if (value == NULL) {
         PyErr_SetString(PyExc_TypeError,
@@ -980,12 +981,13 @@ function___annotations___get_impl(PyFunctionObject *self)
 /*[clinic input]
 @critical_section
 @setter
+@deleter
 function.__annotations__
 [clinic start generated code]*/
 
 static int
 function___annotations___set_impl(PyFunctionObject *self, PyObject *value)
-/*[clinic end generated code: output=a61795d4a95eede4 input=5302641f686f0463]*/
+/*[clinic end generated code: output=a61795d4a95eede4 input=71f6a58c00ac6745]*/
 {
     if (value == Py_None)
         value = NULL;
@@ -1025,12 +1027,13 @@ function___type_params___get_impl(PyFunctionObject *self)
 /*[clinic input]
 @critical_section
 @setter
+@deleter
 function.__type_params__
 [clinic start generated code]*/
 
 static int
 function___type_params___set_impl(PyFunctionObject *self, PyObject *value)
-/*[clinic end generated code: output=038b4cda220e56fb input=3862fbd4db2b70e8]*/
+/*[clinic end generated code: output=038b4cda220e56fb input=c0e33abc5901a2f5]*/
 {
     /* Not legal to del f.__type_params__ or to set it to anything
      * other than a tuple object. */
diff --git a/Python/traceback.c b/Python/traceback.c
index 5bfa28f9c7dc8b6..fe6a465bc64cc94 100644
--- a/Python/traceback.c
+++ b/Python/traceback.c
@@ -176,12 +176,13 @@ tb_lineno_get(PyObject *op, void *Py_UNUSED(_))
 /*[clinic input]
 @critical_section
 @setter
+@deleter
 traceback.tb_next
 [clinic start generated code]*/
 
 static int
 traceback_tb_next_set_impl(PyTracebackObject *self, PyObject *value)
-/*[clinic end generated code: output=d4868cbc48f2adac input=ce66367f85e3c443]*/
+/*[clinic end generated code: output=d4868cbc48f2adac input=936201ff689c5700]*/
 {
     if (!value) {
         PyErr_Format(PyExc_TypeError, "can't delete tb_next attribute");
diff --git a/Tools/clinic/libclinic/clanguage.py b/Tools/clinic/libclinic/clanguage.py
index a8473dba0512460..ab77e7ad6603cdc 100644
--- a/Tools/clinic/libclinic/clanguage.py
+++ b/Tools/clinic/libclinic/clanguage.py
@@ -13,7 +13,8 @@
 from libclinic.function import (
     Module, Class, Function, Parameter, ParamTuple,
     permute_optional_groups,
-    GETTER, SETTER, METHOD_INIT)
+    GETTER, METHOD_INIT,
+    ACCESSORS, SETTERS)
 from libclinic.converters import self_converter
 from libclinic.parse_args import ParseArgsCodeGen
 if TYPE_CHECKING:
@@ -478,12 +479,12 @@ def render_function(
         full_name = f.full_name
         template_dict = {'full_name': full_name}
         template_dict['name'] = f.displayname
-        if f.kind in {GETTER, SETTER}:
+        if f.kind in ACCESSORS:
             template_dict['getset_name'] = f.c_basename.upper()
             template_dict['getset_basename'] = f.c_basename
             if f.kind is GETTER:
                 template_dict['c_basename'] = f.c_basename + "_get"
-            elif f.kind is SETTER:
+            else:
                 template_dict['c_basename'] = f.c_basename + "_set"
                 # Implicitly add the setter value parameter.
                 data.impl_parameters.append("PyObject *value")
@@ -498,7 +499,7 @@ def render_function(
         for converter in converters:
             converter.set_template_dict(template_dict)
 
-        if f.kind not in {SETTER, METHOD_INIT}:
+        if f.kind not in SETTERS | {METHOD_INIT}:
             f.return_converter.render(f, data)
         template_dict['impl_return_type'] = f.return_converter.type
 
diff --git a/Tools/clinic/libclinic/converters.py b/Tools/clinic/libclinic/converters.py
index 76091a9eedc1bff..5539bd2e12e35f5 100644
--- a/Tools/clinic/libclinic/converters.py
+++ b/Tools/clinic/libclinic/converters.py
@@ -8,7 +8,7 @@
 from libclinic.function import (
     Function, Parameter,
     CALLABLE, STATIC_METHOD, CLASS_METHOD, METHOD_INIT, METHOD_NEW,
-    GETTER, SETTER)
+    ACCESSORS)
 from libclinic.codegen import CRenderData, TemplateDict
 from libclinic.converter import (
     CConverter, legacy_converters, add_legacy_c_converter)
@@ -1124,7 +1124,7 @@ def correct_name_for_self(
         f: Function,
         parser: bool = False
 ) -> tuple[str, str]:
-    if f.kind in {CALLABLE, METHOD_INIT, GETTER, SETTER}:
+    if f.kind in {CALLABLE, METHOD_INIT} | ACCESSORS:
         if f.cls:
             return "PyObject *", "self"
         return "PyObject *", "module"
diff --git a/Tools/clinic/libclinic/dsl_parser.py b/Tools/clinic/libclinic/dsl_parser.py
index 4dcbc815cc6f25b..a6b1d2bed5e5dee 100644
--- a/Tools/clinic/libclinic/dsl_parser.py
+++ b/Tools/clinic/libclinic/dsl_parser.py
@@ -18,7 +18,7 @@
     Module, Class, Function, Parameter,
     FunctionKind,
     CALLABLE, STATIC_METHOD, CLASS_METHOD, METHOD_INIT, METHOD_NEW,
-    GETTER, SETTER)
+    ACCESSORS, SETTERS)
 from libclinic.converter import (
     converters, legacy_converters)
 from libclinic.converters import (
@@ -447,21 +447,31 @@ def at_disable(self, *args: str) -> None:
 
     def at_getter(self) -> None:
         match self.kind:
+            case FunctionKind.CALLABLE:
+                self.kind = FunctionKind.GETTER
             case FunctionKind.GETTER:
                 fail("Cannot apply @getter twice to the same function!")
-            case FunctionKind.SETTER:
-                fail("Cannot apply both @getter and @setter to the same function!")
             case _:
-                self.kind = FunctionKind.GETTER
+                fail("Can't set @getter, function is not a normal callable")
 
     def at_setter(self) -> None:
         match self.kind:
-            case FunctionKind.SETTER:
+            case FunctionKind.CALLABLE:
+                self.kind = FunctionKind.SETTER
+            case FunctionKind.SETTER | FunctionKind.SETTER_AND_DELETER:
                 fail("Cannot apply @setter twice to the same function!")
-            case FunctionKind.GETTER:
-                fail("Cannot apply both @getter and @setter to the same function!")
             case _:
-                self.kind = FunctionKind.SETTER
+                fail("Can't set @setter, function is not a normal callable")
+
+    def at_deleter(self) -> None:
+        match self.kind:
+            case FunctionKind.SETTER:
+                # The setter is called with NULL to delete the attribute.
+                self.kind = FunctionKind.SETTER_AND_DELETER
+            case FunctionKind.SETTER_AND_DELETER:
+                fail("Cannot apply @deleter twice to the same function!")
+            case _:
+                fail("Can't set @deleter, @setter is not applied")
 
     def at_staticmethod(self) -> None:
         if self.kind is not CALLABLE:
@@ -592,7 +602,7 @@ def normalize_function_kind(self, fullname: str) -> None:
             fail(f"{name!r} must be a normal method; got '{self.kind}'!")
         if name == '__new__' and (self.kind is not CLASS_METHOD or not cls):
             fail("'__new__' must be a class method!")
-        if self.kind in {GETTER, SETTER} and not cls:
+        if self.kind in ACCESSORS and not cls:
             fail("@getter and @setter must be methods")
 
         # Normalise self.kind.
@@ -605,8 +615,8 @@ def resolve_return_converter(
         self, full_name: str, forced_converter: str
     ) -> CReturnConverter:
         if forced_converter:
-            if self.kind in {GETTER, SETTER}:
-                fail(f"@{self.kind.name.lower()} method cannot define a return type")
+            if self.kind in ACCESSORS:
+                fail("@getter and @setter methods cannot define a return type")
             if self.kind is METHOD_INIT:
                 fail("__init__ methods cannot define a return type")
             ast_input = f"def x() -> {forced_converter}: pass"
@@ -626,7 +636,7 @@ def resolve_return_converter(
             except ValueError:
                 fail(f"Badly formed annotation for {full_name!r}: {forced_converter!r}")
 
-        if self.kind in {METHOD_INIT, SETTER}:
+        if self.kind in {METHOD_INIT} | SETTERS:
             return int_return_converter()
         return CReturnConverter()
 
@@ -732,6 +742,22 @@ def state_modulename_name(self, line: str) -> None:
         self.next(self.state_parameters_start)
 
     def add_function(self, func: Function) -> None:
+        if func.kind in ACCESSORS:
+            # The accessors of the same attribute are rendered into a single
+            # PyGetSetDef entry, which is identified by the C basename, so
+            # they must share it.
+            for other in (func.cls or func.module).functions:
+                if (other.kind in ACCESSORS
+                        and other.full_name == func.full_name):
+                    if (other.kind is func.kind
+                            or {other.kind, func.kind} <= SETTERS):
+                        kind = 'setter' if func.kind in SETTERS else 'getter'
+                        fail(f"Cannot apply @{kind} to "
+                             f"{func.full_name!r} twice")
+                    if other.c_basename != func.c_basename:
+                        fail(f"The accessors of {func.full_name!r} "
+                             f"must have the same C basename")
+
         # Insert a self converter automatically.
         tp, name = correct_name_for_self(func)
         if func.cls and tp == "PyObject *":
@@ -814,9 +840,8 @@ def state_parameters_start(self, line: str) -> None:
             return self.next(self.state_function_docstring, line)
 
         assert self.function is not None
-        if self.function.kind in {GETTER, SETTER}:
-            getset = self.function.kind.name.lower()
-            fail(f"@{getset} methods cannot define parameters")
+        if self.function.kind in ACCESSORS:
+            fail("@getter and @setter methods cannot define parameters")
 
         self.parameter_continuation = ''
         return self.next(self.state_parameter, line)
@@ -1358,7 +1383,7 @@ def format_docstring_signature(
         lines.append(f.displayname)
         if f.forced_text_signature:
             lines.append(f.forced_text_signature)
-        elif f.kind in {GETTER, SETTER}:
+        elif f.kind in ACCESSORS:
             # @getter and @setter do not need signatures like a method or a function.
             return ''
         else:
@@ -1541,7 +1566,7 @@ def format_docstring(self) -> str:
         assert self.function is not None
         f = self.function
         # For the following special cases, it does not make sense to render a docstring.
-        if f.kind in {METHOD_INIT, METHOD_NEW, GETTER, SETTER} and not f.docstring:
+        if f.kind in {METHOD_INIT, METHOD_NEW} | ACCESSORS and not f.docstring:
             return f.docstring
 
         # Enforce the summary line!
diff --git a/Tools/clinic/libclinic/function.py b/Tools/clinic/libclinic/function.py
index 325633eb010608f..cad673045d1c26d 100644
--- a/Tools/clinic/libclinic/function.py
+++ b/Tools/clinic/libclinic/function.py
@@ -60,6 +60,7 @@ class FunctionKind(enum.Enum):
     METHOD_NEW      = enum.auto()
     GETTER          = enum.auto()
     SETTER          = enum.auto()
+    SETTER_AND_DELETER  = enum.auto()
 
     @functools.cached_property
     def new_or_init(self) -> bool:
@@ -76,6 +77,12 @@ def __repr__(self) -> str:
 METHOD_NEW: Final = FunctionKind.METHOD_NEW
 GETTER: Final = FunctionKind.GETTER
 SETTER: Final = FunctionKind.SETTER
+SETTER_AND_DELETER: Final = FunctionKind.SETTER_AND_DELETER
+
+# The kinds which implement the setter of an entry of PyGetSetDef.
+SETTERS: Final = frozenset({SETTER, SETTER_AND_DELETER})
+# The kinds which implement an entry of PyGetSetDef.
+ACCESSORS: Final = SETTERS | {GETTER}
 
 
 @dc.dataclass(repr=False)
@@ -161,7 +168,7 @@ def methoddef_flags(self) -> str | None:
             case FunctionKind.STATIC_METHOD:
                 flags.append('METH_STATIC')
             case _ as kind:
-                acceptable_kinds = {FunctionKind.CALLABLE, FunctionKind.GETTER, FunctionKind.SETTER}
+                acceptable_kinds = {FunctionKind.CALLABLE} | ACCESSORS
                 assert kind in acceptable_kinds, f"unknown kind: {kind!r}"
         if self.coexist:
             flags.append('METH_COEXIST')
diff --git a/Tools/clinic/libclinic/parse_args.py b/Tools/clinic/libclinic/parse_args.py
index 0e99a89d74d7241..b08b949028205d2 100644
--- a/Tools/clinic/libclinic/parse_args.py
+++ b/Tools/clinic/libclinic/parse_args.py
@@ -5,7 +5,8 @@
 from libclinic import fail, warn
 from libclinic.function import (
     Function, Parameter,
-    GETTER, SETTER, METHOD_NEW)
+    GETTER, SETTER, METHOD_NEW,
+    ACCESSORS, SETTERS)
 from libclinic.converter import CConverter
 from libclinic.converters import (
     defining_class_converter, object_converter, self_converter)
@@ -188,6 +189,21 @@ def declare_parser(
         #define {methoddef_name}
     #endif /* !defined({methoddef_name}) */
 """)
+GETSETDEF_PROTOTYPE_IFNDEF: Final[str] = libclinic.normalize_snippet("""
+    #ifndef {getset_name}_GETSETDEF
+        #define {getset_name}_GETSETDEF
+    #endif /* !defined({getset_name}_GETSETDEF) */
+""")
+# The setter is called with NULL to delete the attribute.  Unless @deleter is
+# applied to it, deletion is rejected before the implementation is called.
+SETTER_PREAMBLE: Final[str] = libclinic.normalize_snippet("""
+    if (value == NULL) {{
+        PyErr_Format(PyExc_AttributeError,
+                     "attribute '{name}' of '%.100s' objects cannot be deleted",
+                     Py_TYPE({self_name})->tp_name);
+        return -1;
+    }}
+""", indent=4)
 
 
 class ParseArgsCodeGen:
@@ -328,7 +344,7 @@ def select_prototypes(self) -> None:
             self.methoddef_define = GETTERDEF_PROTOTYPE_DEFINE
             if self.func.docstring:
                 self.docstring_definition = GETSET_DOCSTRING_PROTOTYPE_STRVAR
-        elif self.func.kind is SETTER:
+        elif self.func.kind in SETTERS:
             if self.func.docstring:
                 fail("docstrings are only supported for @getter, not @setter")
             self.return_value_declaration = "int {parser_retval};"
@@ -387,9 +403,12 @@ def parse_no_args(self) -> None:
         if self.func.kind is GETTER:
             self.parser_prototype = PARSER_PROTOTYPE_GETTER
             parser_code = []
-        elif self.func.kind is SETTER:
+        elif self.func.kind in SETTERS:
             self.parser_prototype = PARSER_PROTOTYPE_SETTER
-            parser_code = []
+            if self.func.kind is SETTER:
+                parser_code = [SETTER_PREAMBLE]
+            else:
+                parser_code = []
         elif not self.requires_defining_class:
             # no self.parameters, METH_NOARGS
             self.flags = "METH_NOARGS"
@@ -921,7 +940,10 @@ def process_methoddef(self, clang: CLanguage) -> None:
             self.cpp_endif = "#endif /* " + conditional + " */"
 
             if self.methoddef_define and self.codegen.add_ifndef_symbol(self.func.full_name):
-                self.methoddef_ifndef = METHODDEF_PROTOTYPE_IFNDEF
+                if self.func.kind in ACCESSORS:
+                    self.methoddef_ifndef = GETSETDEF_PROTOTYPE_IFNDEF
+                else:
+                    self.methoddef_ifndef = METHODDEF_PROTOTYPE_IFNDEF
 
     def finalize(self, clang: CLanguage) -> None:
         # add ';' to the end of self.parser_prototype and self.impl_prototype