Laypersons' engagement with science has grown over the last decade, especially in Internet environments. While this development has many benefits, scientists also face the challenge of devaluation and public criticism by laypersons. Embedding this phenomenon in social-psychological theories and research on value-behavior correspondence, we investigated moral threat as a factor influencing laypersons' engagement with science. Across three studies, we hypothesized and found that moral values shape the way laypersons evaluate and communicate about science when these values are threatened in a given situation and central to people's self-concept. However, prior research on the underlying mechanism of moral threat effects cannot fully rule out value salience as an alternative explanation. To close this gap, we situationally induced value salience while varying the degree of moral threat (Study 3). Our findings indicate that moral threat amplifies the influence of moral values on laypersons' evaluation of science above and beyond value salience.