A properly designed test harness is an important part of the quality verification of any software system. However, selection of the most important test cases for the harness is often difficult, since capturing the key characteristics related to the most important functionalities is not obvious. Aspectoriented programming provides means for capturing such cross-cutting issues in systems and promising means for implementing test harnesses for embedded software. This paper studies an example of weaving testing aspects into existing Symbian OS software running on a mobile device. Proposed solution provides a cost-effective, scalable, easily adoptable, and non-tangling tool for testing certain system functionalities.