This article challenges the accepted view that during the period of martial law Taiwan's labour unions were “a useless token.” Focusing on the petroleum and sugar industries, I analyse the incremental process of how party-state control over the labour unions was converted by the workers themselves in Taiwan's national enterprises. In the early 1950s, the KMT's policy of unionizing enterprises was a complementary strategy to reinforce its slow and unsuccessful party-state penetration. With the unions' prominent role in welfare provision, workers were encouraged to develop a sense of stakeholdership. Over the years, labour unions legitimatized the interests of worker members and thus gave rise to an explosion of claim-making activities – what I call “petty bargaining.” By the mid-1980s, labour unions, although still dominated by the KMT, were no longer a Leninist transmission belt, but rather functioned as a de facto complaint centre – an often overlooked precondition for the rise of post-1987 independent labour unionism.