Thomson's goal in presenting her famous Trolley problem is to evince an explanatory weakness in the principle that killing is worse than letting die. Along the way, she tries to evince a similar weakness in the Kantian principle forbidding the use of people as mere means (henceforth: the Kantian prohibition). However, Thomson's negative assessment of the Kantian prohibition is unwarranted, and that is what this paper aims to show. The paper is divided into three sections. In the first, I introduce the Kantian prohibition on using persons as mere means. In the second, I explain where the Trolley problem gets onto the wrong track. To do so, I shall engage with Kleingeld's recent and ingenious Kantian contribution to the trolley problem literature. In the third, I sketch some of what is needed for a Kantian solution to the Trolley problem.