The evolution of capital gains taxation in Australia parallels that in Canada in many respects. Federal income taxes were adopted in both countries during the First World War, and in both jurisdictions the courts interpreted the term "income," the subject of taxation, using United Kingdom judicial concepts that excluded capital gains from the tax base. In the last quarter of the 20th century, both countries amended their income tax laws to capture capital gains, and in both countries concessional rates apply. Initially, the Australian capital gains tax regime had rules that paralleled those in Canada in respect of the application of capital gains tax measures to non-residents, and the list of assets that might generate a capital gains tax liability for non-residents was similar in both countries. Australia changed course just over a decade ago with a decision to limit the income tax liability of non-residents in respect of capital gains to gains on land and land-rich companies alone, albeit with an extended definition of land to capture directly related interests such as exploration and mining rights. Consequently, until this decade, reform of Australia's regime imposing capital gains tax on non-residents focused on the concept of source as a primary driver, with the categories of taxable assets being gradually reduced. However, after more than a decade of unprecedented increases in housing prices in Australia, reform has moved away from addressing source to integrity matters. In Australia, as in Canada, there has been considerable investment in property, particularly residential property, by non-residents in recent years, and the government has sought ways to enhance the enforcement and integrity of the capital gains tax rules applying to non-residents disposing of Australian real property. Since 2013, Australia has proposed three separate measures to ensure integrity within this regime: removal of a concessional rate, introduction of a withholding tax, and removal of the principal residence exemption for non-residents. This article considers the history and development of Australia's capital gains tax regime as it applies to non-residents and examines the recent shift in focus from what is captured in the capital gains source rules to integrity provisions adopted to achieve both compliance and geopolitical objectives.