Traditional Test-Driven Development focuses on development of new units (classes) driven by programmer-facing unit tests. This paper describes our experiences when using business-facing tests (also known as "story tests") to guide the porting of a legacy application. Domain experts specified tests in a tabular format using Excel spreadsheets. Developers automated these spreadsheets in various ways over time: scripts, generation of JUnit source code, and Fit. These tests were run against the legacy system and guided the development of the newly ported system. We found test-driven porting to be an effective way to port a complex application.