This article presents a new interpretation of Conservative attitudes towards house of lords' reform in the early 20th century. Coinciding, as it did, with the introduction of universal adult suffrage, the campaign to reform and strengthen the second chamber has traditionally been understood as a reaction against democracy. Conversely, this article, emphasizing the politics rather than policies of reform, argues that many Conservatives sought to establish a legitimate role for a second chamber within the new democratic settlement and that the campaign for reform is, consequently, better understood as a constitutional means of ‘making safe’, rather than resisting, mass democracy. The account sheds new light on how the impulse behind reform was frequently rooted in a commitment to democracy, how reform commanded the support of a wide cross section of the Conservative parliamentary party, and why the reform campaign had folded by the early 1930s. In doing so, it reframes an important episode that helped close the long-19th-century tradition of constitutional reform in British politics.