```common lisp
(cl:in-package #:sicl-clos)

(defmethod initialize-instance (object &rest keys &key)
  (declare (ignore object keys))
  nil)

(cl:defmethod cl:initialize-instance :after
  ((metaobject metaobject) &rest keys &key &allow-other-keys)
  (apply #'initialize-instance metaobject keys))
```

Set fdefinition of SICL-CLOS:INITIALIZE-INSTANCE to CL:INITIALIZE-INTANCE.
user
```common lisp
(cl:in-package #:sicl-clos)

(setf (fdefinition 'initialize-instance)
      (fdefinition 'cl:initialize-instance))

```
assistant