How do authoritarian regimes prevent protests? One strategy, which frequently accompanies the use of repression, is labeling regime opponents negatively in an attempt to discredit them. This paper considers two frameworks through which negative regime labels about protesters could affect citizens: through persuading them of protesters' illegitimacy, or through signaling the regime's disapproval of protest. We adjudicate the two frameworks with a survey experiment in China which varies regime responses to environmental protest. The results are consistent with the signaling disapproval framework: negative labels do not affect respondents' perceptions of protests but do affect their willingness to protest. Furthermore, these effects depend on respondents' support for the government, and suggest a polarization effect of negative labels. The findings connect research on authoritarian repression and propaganda, suggesting complementarities between the two strategies for regimes.