This research examines whether infants actively contribute to the achievement of joint reference. One possibility is that infants tend to link a label with whichever object they are focused on when they hear the label. If so, infants would make a mapping error when an adult labels a different object than the one occupying their focus. Alternatively, infants may be able to use a speaker's nonverbal cues (e.g., line of regard) to interpret the reference of novel labels. This ability would allow infants to avoid errors when adult labels conflict with infants' focus. 64 16–19-month-olds were taught new labels for novel toys in 2 situations. In follow-in labeling, the experimenter looked at and labeled a toy at which infants were already looking. In discrepant labeling, the experimenter looked at and labeled a different toy than the one occupying infants' focus. Infants' responses to subsequent comprehension questions revealed that they (a) successfully learned the labels introduced during follow-in labeling, and (b) displayed no tendency to make mapping errors after discrepant labeling. Thus infants of only 16 to 19 months understand that a speaker's nonverbal cues are relevant to the reference of object labels; they already can contribute to the social coordination involved in achieving joint reference.