Internet forums are theorized to be important social platforms for peer influence. Current research tends to conceptualize peer influence as adoption processes, investigating whether information received from network contacts stimulate the adoption of a product, service, taste, or attitude. Accordingly, research interest is focused on the first time a product is used. In contrast, the present study investigates mutual and recurrent adaptation between users of an internet forum. This adaptation is theorized to signal engagement in the discussion, which is part of a bonding process. It is essential to internet forum use because this social medium offers no facilities for selecting and evaluating your discussion partners. Using communication accommodation theory, linguistic style matching, and a statistical network model, we analyze style adaptation on an internet forum for the Moroccan minority in the Netherlands. Our results show that posters adapt their style to the style of previous posters within the same thread (discussion) as well as previous posts in other threads within the same section (topic), especially in the case of style elements related to a shared identity. Significant others on the forum—other posters quoted or referenced directly at least two times—also function as style examples provided that they are present in the current discussion. We argue that these effects have wider significance for research into gratifications of online forums for participants and practical relevance for monitoring and moderating discussions on online forums.