A transition t stops a place/transition Petri net if each reachable marking of the net enables only finite occurrence sequences without occurrences of t (i.e., every infinite occurrence sequence enabled at this marking contains occurrences of t). Roughly speaking, when t is stopped then all transitions of the net stop eventually. This contribution shows how to identify stop-transitions of unbounded nets using the coverability graph. Furthermore, the developed technique is adapted to a more general question considering a set of stop-transitions and focussing on a certain part of the net to be stopped. Finally, an implementation of the developed algorithm is presented.