For airline pilots, the call of "checklist complete" is officially prescribed talk to claim that the crew's joint conduct of a checklist is over, and the task can be understood as closed. However, very often this call is not the final talk for the task. This paper uses naturally occurring data, transcriptions of pilots interacting on actual passenger flights, to show that the recipient pilot commonly says something in response. That pilot might say "thank you" or "okay". These two non-official responses do interactional work. They allow the other pilot to know that the call of "checklist complete"was itself heard, and that there is now a shared crew understanding that the checklist is closed. Such an understanding is critical in the airline cockpit where it is crucial to perform tasks in strict sequential order. "Thank you" and "okay" are evidence of pilots' orientation to their work as a progression through a series of tasks, and where there is value in making salient that one task is closed and it is legitimate to move to a next task. The paper examines how officially scripted talk for work is actually realised in situ.