Hi, I'm currently using cells and it works very well, except one thing seems a little unhandy: When defining a model it's possible to use (c-in ..) as an initform to define a slot as a cell, but when instantiating a class you have to supply (c-in ...) instead the normal value, eg. (defmodel x () ((y :accessor y :initarg :y :initform (c-in nil)) ...)) (let ((test (make-instance 'x :y (c-in 1)))) (setf (y test) 2)) works, but instead sth like (let ((test (make-instance 'x :y 1))) (setf (y test) 2)) would be nice. I tried it with (defmethod initialize-instance ((self x) &rest rest) (loop for slot in rest by #'cddr do (let ((value (getf rest slot)) (name (intern (symbol-name slot)))) (setf (slot-value self name) (c-in value))))) but I just get: The slot CELLS::.CELLS is unbound in the object #<X {10032D5FC1}>. [Condition of type UNBOUND-SLOT] Is there any way to get this behavior? kind regards, Bastian