Typescript module doesn't contain my source code

I have a file named Server.js that contains export class Program and <reference path='mscorlib.ts'/>. When I build it with

tsc -t ES5 Server.ts --module commonjs --out Server.js

the generated file contains only the compiled source of mscorlib.ts, but no single sign of Server.ts. I've expected that there would have been an module.exports = {Program: Program} directive besides those sources, though. What could be a source of the problem?