diff --git a/Modules/_remote_debugging_module.c b/Modules/_remote_debugging_module.c
index 564eaef621d..416298d7479 100644
--- a/Modules/_remote_debugging_module.c
+++ b/Modules/_remote_debugging_module.c
@@ -214,6 +214,8 @@ typedef struct {
 #endif
 } RemoteUnwinderObject;
 
+#define RemoteUnwinder_CAST(op) ((RemoteUnwinderObject *)(op))
+
 typedef struct
 {
     int lineno;
@@ -2913,8 +2915,9 @@ static PyMethodDef RemoteUnwinder_methods[] = {
 };
 
 static void
-RemoteUnwinder_dealloc(RemoteUnwinderObject *self)
+RemoteUnwinder_dealloc(PyObject *op)
 {
+    RemoteUnwinderObject *self = RemoteUnwinder_CAST(op);
     PyTypeObject *tp = Py_TYPE(self);
     if (self->code_object_cache) {
         _Py_hashtable_destroy(self->code_object_cache);