diff --git a/Modules/_operator.c b/Modules/_operator.c
index 59987b8f143da2..c287ea2780c528 100644
--- a/Modules/_operator.c
+++ b/Modules/_operator.c
@@ -999,13 +999,13 @@ static struct PyMethodDef operator_methods[] = {
 
 
 static PyObject *
-text_signature(PyObject *self, void *Py_UNUSED(ignored))
+text_signature(PyObject *Py_UNUSED(self), void *Py_UNUSED(closure))
 {
     return PyUnicode_FromString("(obj, /)");
 }
 
 static PyGetSetDef common_getset[] = {
-    {"__text_signature__", text_signature, (setter)NULL},
+    {"__text_signature__", text_signature, NULL},
     {NULL}
 };
 
@@ -1019,6 +1019,8 @@ typedef struct {
     vectorcallfunc vectorcall;
 } itemgetterobject;
 
+#define itemgetterobject_CAST(op)   ((itemgetterobject *)(op))
+
 // Forward declarations
 static PyObject *
 itemgetter_vectorcall(PyObject *, PyObject *const *, size_t, PyObject *);
@@ -1069,49 +1071,52 @@ itemgetter_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
         }
     }
 
-    ig->vectorcall = (vectorcallfunc)itemgetter_vectorcall;
+    ig->vectorcall = itemgetter_vectorcall;
     PyObject_GC_Track(ig);
     return (PyObject *)ig;
 }
 
 static int
-itemgetter_clear(itemgetterobject *ig)
+itemgetter_clear(PyObject *op)
 {
+    itemgetterobject *ig = itemgetterobject_CAST(op);
     Py_CLEAR(ig->item);
     return 0;
 }
 
 static void
-itemgetter_dealloc(itemgetterobject *ig)
+itemgetter_dealloc(PyObject *op)
 {
-    PyTypeObject *tp = Py_TYPE(ig);
-    PyObject_GC_UnTrack(ig);
-    (void)itemgetter_clear(ig);
-    tp->tp_free(ig);
+    PyTypeObject *tp = Py_TYPE(op);
+    PyObject_GC_UnTrack(op);
+    (void)itemgetter_clear(op);
+    tp->tp_free(op);
     Py_DECREF(tp);
 }
 
 static int
-itemgetter_traverse(itemgetterobject *ig, visitproc visit, void *arg)
+itemgetter_traverse(PyObject *op, visitproc visit, void *arg)
 {
+    itemgetterobject *ig = itemgetterobject_CAST(op);
     Py_VISIT(Py_TYPE(ig));
     Py_VISIT(ig->item);
     return 0;
 }
 
 static PyObject *
-itemgetter_call(itemgetterobject *ig, PyObject *args, PyObject *kw)
+itemgetter_call(PyObject *op, PyObject *args, PyObject *kw)
 {
     assert(PyTuple_CheckExact(args));
     if (!_PyArg_NoKeywords("itemgetter", kw))
         return NULL;
     if (!_PyArg_CheckPositional("itemgetter", PyTuple_GET_SIZE(args), 1, 1))
         return NULL;
+    itemgetterobject *ig = itemgetterobject_CAST(op);
     return itemgetter_call_impl(ig, PyTuple_GET_ITEM(args, 0));
 }
 
 static PyObject *
-itemgetter_vectorcall(PyObject *ig, PyObject *const *args,
+itemgetter_vectorcall(PyObject *op, PyObject *const *args,
                       size_t nargsf, PyObject *kwnames)
 {
     if (!_PyArg_NoKwnames("itemgetter", kwnames)) {
@@ -1121,7 +1126,8 @@ itemgetter_vectorcall(PyObject *ig, PyObject *const *args,
     if (!_PyArg_CheckPositional("itemgetter", nargs, 1, 1)) {
         return NULL;
     }
-    return itemgetter_call_impl((itemgetterobject *)ig, args[0]);
+    itemgetterobject *ig = itemgetterobject_CAST(op);
+    return itemgetter_call_impl(ig, args[0]);
 }
 
 static PyObject *
@@ -1161,12 +1167,13 @@ itemgetter_call_impl(itemgetterobject *ig, PyObject *obj)
 }
 
 static PyObject *
-itemgetter_repr(itemgetterobject *ig)
+itemgetter_repr(PyObject *op)
 {
     PyObject *repr;
     const char *reprfmt;
+    itemgetterobject *ig = itemgetterobject_CAST(op);
 
-    int status = Py_ReprEnter((PyObject *)ig);
+    int status = Py_ReprEnter(op);
     if (status != 0) {
         if (status < 0)
             return NULL;
@@ -1175,13 +1182,14 @@ itemgetter_repr(itemgetterobject *ig)
 
     reprfmt = ig->nitems == 1 ? "%s(%R)" : "%s%R";
     repr = PyUnicode_FromFormat(reprfmt, Py_TYPE(ig)->tp_name, ig->item);
-    Py_ReprLeave((PyObject *)ig);
+    Py_ReprLeave(op);
     return repr;
 }
 
 static PyObject *
-itemgetter_reduce(itemgetterobject *ig, PyObject *Py_UNUSED(ignored))
+itemgetter_reduce(PyObject *op, PyObject *Py_UNUSED(dummy))
 {
+    itemgetterobject *ig = itemgetterobject_CAST(op);
     if (ig->nitems == 1)
         return Py_BuildValue("O(O)", Py_TYPE(ig), ig->item);
     return PyTuple_Pack(2, Py_TYPE(ig), ig->item);
@@ -1190,7 +1198,7 @@ itemgetter_reduce(itemgetterobject *ig, PyObject *Py_UNUSED(ignored))
 PyDoc_STRVAR(reduce_doc, "Return state information for pickling");
 
 static PyMethodDef itemgetter_methods[] = {
-    {"__reduce__", (PyCFunction)itemgetter_reduce, METH_NOARGS,
+    {"__reduce__", itemgetter_reduce, METH_NOARGS,
      reduce_doc},
     {NULL}
 };
@@ -1239,6 +1247,8 @@ typedef struct {
     vectorcallfunc vectorcall;
 } attrgetterobject;
 
+#define attrgetterobject_CAST(op)   ((attrgetterobject *)(op))
+
 // Forward declarations
 static PyObject *
 attrgetter_vectorcall(PyObject *, PyObject *const *, size_t, PyObject *);
@@ -1348,32 +1358,34 @@ attrgetter_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
 
     ag->attr = attr;
     ag->nattrs = nattrs;
-    ag->vectorcall = (vectorcallfunc)attrgetter_vectorcall;
+    ag->vectorcall = attrgetter_vectorcall;
 
     PyObject_GC_Track(ag);
     return (PyObject *)ag;
 }
 
 static int
-attrgetter_clear(attrgetterobject *ag)
+attrgetter_clear(PyObject *op)
 {
+    attrgetterobject *ag = attrgetterobject_CAST(op);
     Py_CLEAR(ag->attr);
     return 0;
 }
 
 static void
-attrgetter_dealloc(attrgetterobject *ag)
+attrgetter_dealloc(PyObject *op)
 {
-    PyTypeObject *tp = Py_TYPE(ag);
-    PyObject_GC_UnTrack(ag);
-    (void)attrgetter_clear(ag);
-    tp->tp_free(ag);
+    PyTypeObject *tp = Py_TYPE(op);
+    PyObject_GC_UnTrack(op);
+    (void)attrgetter_clear(op);
+    tp->tp_free(op);
     Py_DECREF(tp);
 }
 
 static int
-attrgetter_traverse(attrgetterobject *ag, visitproc visit, void *arg)
+attrgetter_traverse(PyObject *op, visitproc visit, void *arg)
 {
+    attrgetterobject *ag = attrgetterobject_CAST(op);
     Py_VISIT(ag->attr);
     Py_VISIT(Py_TYPE(ag));
     return 0;
@@ -1413,17 +1425,19 @@ dotted_getattr(PyObject *obj, PyObject *attr)
 }
 
 static PyObject *
-attrgetter_call(attrgetterobject *ag, PyObject *args, PyObject *kw)
+attrgetter_call(PyObject *op, PyObject *args, PyObject *kw)
 {
     if (!_PyArg_NoKeywords("attrgetter", kw))
         return NULL;
     if (!_PyArg_CheckPositional("attrgetter", PyTuple_GET_SIZE(args), 1, 1))
         return NULL;
+    attrgetterobject *ag = attrgetterobject_CAST(op);
     return attrgetter_call_impl(ag, PyTuple_GET_ITEM(args, 0));
 }
 
 static PyObject *
-attrgetter_vectorcall(PyObject *ag, PyObject *const *args, size_t nargsf, PyObject *kwnames)
+attrgetter_vectorcall(PyObject *op, PyObject *const *args,
+                      size_t nargsf, PyObject *kwnames)
 {
     if (!_PyArg_NoKwnames("attrgetter", kwnames)) {
         return NULL;
@@ -1432,7 +1446,8 @@ attrgetter_vectorcall(PyObject *ag, PyObject *const *args, size_t nargsf, PyObje
     if (!_PyArg_CheckPositional("attrgetter", nargs, 1, 1)) {
         return NULL;
     }
-    return attrgetter_call_impl((attrgetterobject *)ag, args[0]);
+    attrgetterobject *ag = attrgetterobject_CAST(op);
+    return attrgetter_call_impl(ag, args[0]);
 }
 
 static PyObject *
@@ -1505,10 +1520,11 @@ attrgetter_args(attrgetterobject *ag)
 }
 
 static PyObject *
-attrgetter_repr(attrgetterobject *ag)
+attrgetter_repr(PyObject *op)
 {
     PyObject *repr = NULL;
-    int status = Py_ReprEnter((PyObject *)ag);
+    attrgetterobject *ag = attrgetterobject_CAST(op);
+    int status = Py_ReprEnter(op);
     if (status != 0) {
         if (status < 0)
             return NULL;
@@ -1532,22 +1548,22 @@ attrgetter_repr(attrgetterobject *ag)
             Py_DECREF(attrstrings);
         }
     }
-    Py_ReprLeave((PyObject *)ag);
+    Py_ReprLeave(op);
     return repr;
 }
 
 static PyObject *
-attrgetter_reduce(attrgetterobject *ag, PyObject *Py_UNUSED(ignored))
+attrgetter_reduce(PyObject *op, PyObject *Py_UNUSED(dummy))
 {
+    attrgetterobject *ag = attrgetterobject_CAST(op);
     PyObject *attrstrings = attrgetter_args(ag);
     if (attrstrings == NULL)
         return NULL;
-
     return Py_BuildValue("ON", Py_TYPE(ag), attrstrings);
 }
 
 static PyMethodDef attrgetter_methods[] = {
-    {"__reduce__", (PyCFunction)attrgetter_reduce, METH_NOARGS,
+    {"__reduce__", attrgetter_reduce, METH_NOARGS,
      reduce_doc},
     {NULL}
 };
@@ -1602,13 +1618,15 @@ typedef struct {
     vectorcallfunc vectorcall;
 } methodcallerobject;
 
+#define methodcallerobject_CAST(op) ((methodcallerobject *)(op))
 
 #define _METHODCALLER_MAX_ARGS 8
 
 static PyObject *
-methodcaller_vectorcall(methodcallerobject *mc, PyObject *const *args,
-        size_t nargsf, PyObject* kwnames)
+methodcaller_vectorcall(PyObject *op, PyObject *const *args,
+                        size_t nargsf, PyObject* kwnames)
 {
+    methodcallerobject *mc = methodcallerobject_CAST(op);
     if (!_PyArg_CheckPositional("methodcaller", PyVectorcall_NARGS(nargsf), 1, 1)
         || !_PyArg_NoKwnames("methodcaller", kwnames)) {
         return NULL;
@@ -1661,7 +1679,7 @@ _methodcaller_initialize_vectorcall(methodcallerobject* mc)
         mc->vectorcall_kwnames = NULL;
     }
 
-    mc->vectorcall = (vectorcallfunc)methodcaller_vectorcall;
+    mc->vectorcall = methodcaller_vectorcall;
     return 0;
 }
 
@@ -1721,8 +1739,9 @@ methodcaller_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
 }
 
 static void
-methodcaller_clear(methodcallerobject *mc)
+methodcaller_clear(PyObject *op)
 {
+    methodcallerobject *mc = methodcallerobject_CAST(op);
     Py_CLEAR(mc->name);
     Py_CLEAR(mc->args);
     Py_CLEAR(mc->kwds);
@@ -1731,18 +1750,19 @@ methodcaller_clear(methodcallerobject *mc)
 }
 
 static void
-methodcaller_dealloc(methodcallerobject *mc)
+methodcaller_dealloc(PyObject *op)
 {
-    PyTypeObject *tp = Py_TYPE(mc);
-    PyObject_GC_UnTrack(mc);
-    methodcaller_clear(mc);
-    tp->tp_free(mc);
+    PyTypeObject *tp = Py_TYPE(op);
+    PyObject_GC_UnTrack(op);
+    (void)methodcaller_clear(op);
+    tp->tp_free(op);
     Py_DECREF(tp);
 }
 
 static int
-methodcaller_traverse(methodcallerobject *mc, visitproc visit, void *arg)
+methodcaller_traverse(PyObject *op, visitproc visit, void *arg)
 {
+    methodcallerobject *mc = methodcallerobject_CAST(op);
     Py_VISIT(mc->name);
     Py_VISIT(mc->args);
     Py_VISIT(mc->kwds);
@@ -1753,9 +1773,10 @@ methodcaller_traverse(methodcallerobject *mc, visitproc visit, void *arg)
 }
 
 static PyObject *
-methodcaller_call(methodcallerobject *mc, PyObject *args, PyObject *kw)
+methodcaller_call(PyObject *op, PyObject *args, PyObject *kw)
 {
     PyObject *method, *obj, *result;
+    methodcallerobject *mc = methodcallerobject_CAST(op);
 
     if (!_PyArg_NoKeywords("methodcaller", kw))
         return NULL;
@@ -1772,11 +1793,12 @@ methodcaller_call(methodcallerobject *mc, PyObject *args, PyObject *kw)
 }
 
 static PyObject *
-methodcaller_repr(methodcallerobject *mc)
+methodcaller_repr(PyObject *op)
 {
+    methodcallerobject *mc = methodcallerobject_CAST(op);
     PyObject *argreprs, *repr = NULL, *sep, *joinedargreprs;
     Py_ssize_t numtotalargs, numposargs, numkwdargs, i;
-    int status = Py_ReprEnter((PyObject *)mc);
+    int status = Py_ReprEnter(op);
     if (status != 0) {
         if (status < 0)
             return NULL;
@@ -1789,13 +1811,13 @@ methodcaller_repr(methodcallerobject *mc)
 
     if (numtotalargs == 0) {
         repr = PyUnicode_FromFormat("%s(%R)", Py_TYPE(mc)->tp_name, mc->name);
-        Py_ReprLeave((PyObject *)mc);
+        Py_ReprLeave(op);
         return repr;
     }
 
     argreprs = PyTuple_New(numtotalargs);
     if (argreprs == NULL) {
-        Py_ReprLeave((PyObject *)mc);
+        Py_ReprLeave(op);
         return NULL;
     }
 
@@ -1843,13 +1865,14 @@ methodcaller_repr(methodcallerobject *mc)
 
 done:
     Py_DECREF(argreprs);
-    Py_ReprLeave((PyObject *)mc);
+    Py_ReprLeave(op);
     return repr;
 }
 
 static PyObject *
-methodcaller_reduce(methodcallerobject *mc, PyObject *Py_UNUSED(ignored))
+methodcaller_reduce(PyObject *op, PyObject *Py_UNUSED(dummy))
 {
+    methodcallerobject *mc = methodcallerobject_CAST(op);
     if (!mc->kwds || PyDict_GET_SIZE(mc->kwds) == 0) {
         Py_ssize_t i;
         Py_ssize_t callargcount = PyTuple_GET_SIZE(mc->args);
@@ -1882,7 +1905,7 @@ methodcaller_reduce(methodcallerobject *mc, PyObject *Py_UNUSED(ignored))
 }
 
 static PyMethodDef methodcaller_methods[] = {
-    {"__reduce__", (PyCFunction)methodcaller_reduce, METH_NOARGS,
+    {"__reduce__", methodcaller_reduce, METH_NOARGS,
      reduce_doc},
     {NULL}
 };
@@ -1985,7 +2008,7 @@ operator_clear(PyObject *module)
 static void
 operator_free(void *module)
 {
-    operator_clear((PyObject *)module);
+    (void)operator_clear((PyObject *)module);
 }
 
 static struct PyModuleDef operatormodule = {