—Mashup tools are becoming increasingly important enabling users to compose services and processes on the Web. Most existing tools focus on Web-based interfaces, usability, and visual languages for creating mashups. A major challenge that has received limited attention is context-awareness and adaptivity of service mashups. In this paper we focus on two main aspects: First, a service capability model describing service characteristics that can be tracked and matched against the requirements associated with service mashups and second an algorithm to recommend refinements such as replacing services within mashups. We implemented a set of adaptation algorithms to validate our approach in real service-oriented systems.