This article explores workplace cheating taking place in the oil-shale mines in the north-eastern part of Soviet Estonia from the 1950s to 1980s. The author focuses on four different types of workplace cheating and misbehaviour: fiddling with production numbers; fiddling with health and safety; drinking and absenteeism; and stealing. These were not the only types of cheating taking place, but were more significant in the mining area and most prevalent in the memoirs and oral histories recorded or published in the 2000s. Analysing these four types, the author carves out the moral code of workplace cheating, as well as the acceptable levels of each of these activities. She also emphasises that this type of cheating was closely tied to the overall logic of the Soviet system in which fiddling required co-operation with colleagues, often between workers and managers, while also looking out for individual interests. Further, the author shows that due to the similar shared experiences of workers and engineers/managers, their overall class experience and consciousness, including their moral code regarding cheating at the workplace, was very similar.