Internet memes are messages—usually in the form of images, videos, and phrases—that are spread in Internet spaces, and which undergo selective changes by Internet users as they propagate. Memes using negative stereotypes, a form of disparagement humor, may serve to communicate bias online. The objectives of the present research were to investigate how antistereotyping norms expressed in an online image-hosting context may affect behavior, and to examine the moderating role played by preexisting attitudes toward stereotyping. White participants commented on 1 of 2 Internet memes that derogated Asians: 1 was presented as humorous, and the other was presented as serious. Participants also saw comments supposedly made by others; 1 comment was either neutral or an objection to the stereotypic portrayal of Asians (either by an Asian or by an unstated-race commenter). Participants objected to the memes more often when they saw an unstated-race commenter object, but not when an Asian commenter objected, which suggests that the presence of advocates for marginalized groups is important in online social contexts. Participants who were more supportive of stereotyping were less likely to object to the memes and found the memes to be more socially acceptable than other participants did. These same participants were particularly accepting when the meme was humorous; thus, assuming a noncritical mindset toward disparagement humor may be facilitated by preexisting support of stereotyping.