In recent years, the theory that prediction is an important part of language processing has gained considerable attention (see Huettig, 2015, for overview). There is a large body of empirical evidence which suggests that language users’ ability to anticipate interlocutors’ upcoming utterances is one of the reasons why interactive speech can be so effortless, smooth, and efficient in nature (e.g. Wicha et al., 2004; van Berkum et al., 2005). The present study aimed to investigate whether the language production module is affected by prediction of another individual’s utterances using a joint language production task designed to establish whether simulation of an interlocutor’s utterance occurs automatically, even if this hinders one’s own speech production. The experiment aimed to replicate the finding of an interference effect in a joint naming task (Gambi et al., 2015), and investigate whether the same patterns could be found within a clearer social context where a partner was co-present in the same room. Participants named pictures of objects while their partners concurrently named or categorised congruent or incongruent stimuli. Analyses of naming onset latencies indicate that individuals may partially co-represent their partner’s utterances and that this shared representation influences language production. Congruency in task and stimuli display facilitated naming compared to incongruent trials which showed a tendency to impede production latencies. This finding of a social effect in a setting where simulation of language content is not necessary may suggest that some kind of anticipatory processing is an underlying feature of comprehension.