It seems that we can't use setValue:forKey if we have pointer to some primitive type, for examples int*. Look at this -> http://lists.apple.com/archives/cocoa-dev/2006/May/msg00343.html. But luckily we can find out actual name of getter/setter function if some property is using those functions -> @property (nonatomic, assign, getter = get_prop_int_gtr_ptr, setter = set_prop_int_ptr:) int *prop_int_cst_ptr;