The Shiwiar are an indigenous nation of Ecuador and Peru, and they are one of five ethnic groups collectively known as the Jivaroan people. In stark contrast to the other Jivaroan groups, the Shiwiar have largely been overlooked by local governments until recently and are still popularly considered to be an offshoot of their closely related neighbours, the Achuar. This has led to a strong desire within the Shiwiar community to be recognised as an independent group. In order to achieve this, the Shiwiar leaders have made use of linguistic prescriptivism as a tool to emphasise the distinction between the Shiwiar language and the other Jivaroan languages. A slightly modified orthography was advocated and the use of particular lexical items was encouraged. However, this strategy has proved to be unsuccessful. Instead of generating a sense of union and independence among the Shiwiar nation, it has resulted in uncertainty and confusion regarding language use and identity. It is argued here that although prescriptive language planning has been successful in nation-building initiatives around the world, the sociolinguistic situation of Shiwiar does not allow for the necessary conditions for a prescriptive campaign to be effective.