Speakers sometimes express information in gestures that they do not express in speech. This research developed a system that could be used to assess the redundancy of gesture and speech in a narrative task. This system was then applied to examine whether children and adults produce non-redundant gesture–speech combinations at similar rates. The coding system was developed based on a sample of 30 children. A crucial feature of the system is that gesture meanings can be assessed based on form alone; thus, the meanings speakers express in gesture and speech can be assessed independently and compared. Narrative data were collected from a new sample of 17 children (ages 5–10), as well as a sample of 20 adults, and the paper determined the average proportion of non-redundant gesture–speech combinations produced by individuals in each group. Children produced more non-redundant gesture–speech combinations than adults, both at the clause level and at the word level. These findings suggest that gesture–speech integration is not constant over the life span, but instead appears to change with development.