- let previous_work = previous_header.header.work();
- if work > (previous_work << 2) || work < (previous_work >> 2) {
+ let target = self.header.target();
+ let previous_target = previous_header.header.target();
+ let min_target = previous_target.min_difficulty_transition_threshold();
+ let max_target = previous_target.max_difficulty_transition_threshold();
+ if target > max_target || target < min_target {