Ktor's default response is 404 even if there's a route

I'm using the Ktor web server/framework to write a web service in Kotlin. I added a handler for a certain route, put some code in it, but found that clients got a 404 error when accessing that path. Apparently the problem was that, since I didn't need to send any data to the client when handling that request, I never used one of the response methods on call - the status code defaulted to 404. Setting the status code with call.response.status produced my expected behavior.