Whether we like it or not, AI is already part of peer review. Our community has barely begun to discuss how reviewers use it or what norms should govern that use. We have independently developed AI-assisted reviewing workflows and discovered that our practices converged on similar boundaries. In this essay, we describe those workflows in detail, report what changed as a result of using AI, and reflect on what the experience revealed about our own longstanding reviewing habits. We close with an initial set of guidelines as a starting point for the community to develop explicit, shared norms for AI use in reviewing.